Practice News

Aug 13, 2021 Covid update

I’m going to start with a personal note. A close family member of mine was admitted to the hospital last night with Covid19 pneumonia, and this person’s spouse also has Covid19. Both these family members were vaccinated and wearing masks regularly when out of the house. They were limiting trips outside the home, yet they did not stay at home completely.

This is a serious case which will develop one way or the other over the next few days. It is also a reminder that this delta variant is highly contagious and causing a huge number of infections even in those who are vaccinated. This surge is very real, and the numbers are now approaching those seen at the beginning of the year, when things were at their worst. In Tucson, the hospitals had been relatively spared (unlike some other parts of the country), yet just this week the number of patients admitted with Covid19 has almost tripled at TMC.

I do believe the number of breakthrough cases is being under reported right now, yet I also believe the number will continue to be extremely low. Currently, less than one percent of new Covid19 cases are officially due to breakthrough infections. Despite my family member’s case, hospitalizations among those who have been vaccinated remain rare.

There is no proof that an earlier Covid19 infection will protect against reinfection. I am intrigued by the number of professional athletes testing positive again for Covid19 despite either having infections in the past or being vaccinated. For the time being, I feel a prior Covid19 infection only provides a limited window of protection. How long that protection will last has yet to be discerned.

Likewise, there are strong opinions that vaccines also offer only a limited duration of protection. Unfortunately, no strong data exists to support giving a third booster shot of the Pfizer or Moderna vaccines to the population as a whole. For immunocompromised individuals, such as those who have received an organ transplant or who are on chemotherapy for cancer (or other immunocompromising medications) the FDA is now recommending a third shot. Israel and Germany have started giving third shots to older individuals, yet while the current vaccine protects against the delta variant, a different formulation is being developed which may work even better.

I suspect some of the hesitancy to recommend a third dose in the US for everyone may center around the concern the current formulation will not effectively boost protection against the delta variant. However, I do not know this for a fact.

Interestingly, Covid19 can have several symptoms, and not everyone gets the classic upper respiratory presentation of congestion, cough, and so on. Some patients have been reluctant to get Covid tested when advised, yet given the current situation, any symptoms which could even be remotely related to Covid require a Covid test so we can know better what we may be dealing with.

No one wishes to return to what we experienced last year, yet not taking a mask off in public is one way to reduce the risk of getting infected. Masks can be uncomfortable, yet many individuals in many different professions have been required to wear masks for decades to protect themselves. Depressingly, Covid19 and the prevention recommendations have become increasingly politicized and the messaging from public health officials is constantly attacked. More rational discussion needs to occur.

Thank you.

Covid19 Update 7-23-21

Covid19 has unfortunately become a major focus again. The hope that the pandemic was gone is now giving way to the realization that we are entering another surge like last summer. Nationwide, the number of cases and hospitalizations is increasing dramatically. Deaths have not risen quite as much, yet the death rate often trails the increase in case numbers by 2-4 weeks.

Here in Arizona, our seven-day averages have gone from just under 400 cases a day in early June to over 1000 cases a day this past week. Thankfully, so far hospitalization numbers have not increased quite as dramatically, yet they are up from June. Both here and nationwide, almost all hospitalized Covid19 patients have been unvaccinated.

The efficacy of the vaccines has been questioned recently, with several reports of people testing positive for Covid19 despite being vaccinated. This development is not surprising, as vaccines do not necessarily prevent people from developing a disease. The goal of a vaccine is to prevent someone from getting a more serious case or dying from that disease, and so far, the Covid19 vaccines are working well in achieving that goal.

The fear however is that somewhere in time, the vaccines will become less effective either due to “wearing off” or because a new variant will develop which will not be responsive to the current vaccine formulations.

With regards to the first issue, there has been an ongoing debate over the last month about whether a booster shot will be needed. As mentioned previously, both Pfizer and Moderna have been working on boosters and have discussed with the FDA about approving a booster dose. However, currently the FDA and the CDC do not feel the available evidence supports doing a mass booster vaccine.

The emergence of a variant that will ultimately be resistant to all our current vaccines is also being heavily discussed in the news right now. This concern stems from the inability to achieve over 70% immunity in the population through vaccine. This inability allows the virus to spread and potentially mutate. If herd immunity had been achieved by now, this concern would be lower.

The reluctance of many people to getting vaccinated is contributing to the potential for a totally resistant variant. I am firmly convinced that the Pfizer and Moderna vaccines will receive full FDA approval in the next year, which may help some to feel more comfortable getting vaccinated. However, all the recent variants including Delta and now Lambda have originated outside of the US, so herd immunity will be necessary worldwide to ultimately stop the emergence of variants. Nevertheless, just like a brush fire can not expand if it is denied fuel, the expansion of Covid19 in the US would be significantly reduced if we achieve herd immunity.

Finally, the need for masks continues to be discussed. Officially, the CDC still states vaccinated people do no need to wear masks in public. However, many physicians (including myself) are recommending that when in a place where unvaccinated people may be, you should wear a mask. Since we are still concerned vaccinated people may be able to infect others, at the very least it may help slow down the spread of the Delta variant.

Take care.

Covid update July 1, 2021

There have been two very confusing issues recently regarding Covid 19 here in the US.

First off is mask wearing. Several different recommendations have been issued recently. The CDC position since mid-May has been that no mask is necessary in public if you have been vaccinated. The alternative recommendation coming from WHO and some local health departments such as Los Angeles County is you should continue to wear masks when out in public despite being vaccinated. This position is based on the concern that the Delta variant is so contagious that even being vaccinated may not protect you from either spreading it or getting it yourself (though the Pfizer and Moderna vaccines protect very well against it).

The reality is no one really knows, yet Dr. Walensky, the new head of the CDC, offered a compromise position yesterday stating that being unmasked remains ok unless the local health authorities in your area have recommended otherwise. Personally, I continue to wear a mask in public since I am not yet comfortable with the risk without one. Here in Arizona though, there is currently no formal recommendation overriding the CDC guideline to being unmasked if vaccinated. Of note is that having had Covid earlier on is not felt to be protective against the Delta variant and therefore masking is being recommended by some for this group.

The second issue is if a booster or additional dose of vaccine will be needed beyond what is already recommended. This conversation started back in Dec 2020 and like everything Covid related it is a frequently changing one.
In brief, the most recent data coming out is that the mRNA vaccines (specifically Pfizer and Moderna) seem to provide long term protection against both infection and death from Covid19. The adenovirus-based vaccines (Johnson and Johnson here in the US and Astra Zeneca in Europe and other parts of the world) protect against death from Covid19 yet may not be as protective against infection with the new variants (specifically the Delta variant).

There are some interesting studies just recently published showing that people who received a Pfizer vaccine a few months after receiving the Astra Zeneca vaccine had a significant increase in antibody levels against Covid19. This mixing of different formulations of Covid19 vaccines has been discussed for months in the medical literature. What is uncertain is if this will lead to fewer symptomatic infections or deaths. Also unknown is whether those who got a Johnson and Johnson vaccine should get a Pfizer or Moderna vaccine or if administering a third Pfizer or Moderna vaccine will provide even better protection or be necessary at all. Stay tuned for more on this subject. Right now, no additional shots are being recommended here in the US.

(The day after I released this message a study was publicized looking at a third and even fourth vaccine dose for those individuals who failed to make antibodies with the first two doses. This group mainly consisted of patients who were on chemotherapy for cancer or on other medications that suppressed the immune function. Although the number in the test group was small they did show that with a second series of two shots this group finally formed antibodies to the virus and thus were now probably protected. It will be interesting to see how these findings change what is done.)

The number of cases here in Arizona has been slowly increasing over the last 4 weeks. While nowhere near the numbers when things were really bad, the average daily number of new cases has increased from below 400 a day to an average of 540 a day over the last eight days. Hospitalizations for Covid 19 are fluctuating yet based on both numbers reported by the state and by TMC they are up a little.

Finally, I am giving my employees a four-day July 4th weekend so the office will be closed on Friday July 2 and Monday July 5. I will remain available by cell phone or through the answering service, yet hopefully everyone will have a joyful and healthy holiday celebration and not need to speak with me. I will be back in the office July 8 after just hanging out with my family at home. Take care.

April 16, 2021 Covid update

There continues to be conflicting information on the risks of Covid 19 in the news. For instance, just 2 weeks ago the CDC issued new travel guidelines stating anyone fully immunized may travel without any restrictions so long as they continue to wear masks while in public. Some states have even eliminated any restrictions on large crowd gatherings and mask wearing.

However, also in the news is the continuing rise of infections in certain areas of the country, and new reports detailing people getting Covid19 despite being vaccinated. In addition, the Johnson and Johnson vaccine has been temporarily stopped due to a small number of cases of serious blood clotting issues.

So how does one make sense of it all?

First off, we must understand that all our knowledge is being acquired as this pandemic progresses. Realize that what we state as factual today may turn out to be incorrect or incomplete just 2-4 weeks from now. However, we only can use the information we have at hand, so we are forced to advise and educate with those limitations.

With regards to vaccine protections, despite the new variants the vaccines do appear to be working remarkably well. No vaccine is perfect, and the very small number of breakthrough infections (less than 1%) is not concerning at this point in time. There is a big effort to more fully understand why these failures may be occurring, yet that information will not be available for a while.

Interestingly, while both technologies used in the Covid vaccines (mRNA and Adenovirus) have never been fully utilized clinically, the seemingly new mRNA methodology used in the Pfizer and Moderna products actually has science dating back over ten years and is not novel nor untested. With the Adenovirus vaccines (the Johnson and Johnson and Astra Zeneca products), there appears to be something on the Adenovirus used that may trigger the body in rare circumstances to attack platelets and cause blood clots.

Because all these vaccines are new, any reported serious side effect will lead to a pause in administration while experts take the time to analyze the data and figure out whether to continue using the product. In the case of Astra Zeneca, vaccines were continued (although not without some countries stopping its use altogether) I anticipate we will see the Johnson and Johnson vaccine return with some restrictions.

Finally, while case numbers in Arizona appear to be stable there is discussion in some parts of the medical community that the situation on the border represents a very real threat to cause super spreader events here in Arizona. Testing does not seem ideally coordinated and may not even be done in some areas, and consequently we are in a situation where “we don’t know what we don’t know” (as an infectious disease colleague of mine has stated). Until we have a much higher rate of immunization then the 33% that we currently have, Arizona (and other southern border states) could be at a higher risk then appreciated. Only routine testing of everyone detained at the border will help us figure this out. So please continue to wear a mask in public even if you are immunized.

Take care.

March 19, 2021 Covid update

The news and messaging regarding the pandemic over the last two weeks have been extremely confusing. On the one hand, in some states (including Arizona) the number of cases and hospitalizations continue to decline. In other states (specifically Michigan) there has been an alarming increase in Covid19 cases. Governors of several states are relaxing restrictions on indoor gatherings and mask wearing while public health experts maintain that we may just be experiencing the quiet before the next bad surge.

Knowing who is right is essentially impossible at this moment in time. However, it is important to understand why there is this divide in opinion.

Basically, three main elements worry public health experts. First and foremost is the emergence of Covid19 mutants. These variant strains of the virus are more contagious and according to recently published studies, more deadly. The UK variant known as B1.1.7, which is becoming the dominant strain in the US, has been shown to be up to twice as deadly than the original (or wild type) strain of the virus. Thankfully, current vaccines do protect against this specific variant.

The second major worry is that only 16% of the US population has been vaccinated against Covid19. Many people may still get the virus and become very ill or even die from it. We are literally in an “arms race” trying to immunize people as quickly as possible. As the percentage of people immunized increases, concerns will ease, yet we need at least 70% of the population to be immunized for ideal protection (also described as herd immunity).

The third element is the continuous surge in cases and deaths whenever people stop wearing masks and start congregating in closed spaces. The worry is people will think the risk is past, yet with the more contagious and deadly strains now emerging, nothing could be further from the truth.

On the other hand, we know that Covid19 can be very unpredictable. Why are some states improving when others are worsening? Why in the first surge a year ago were only some areas (such as New York City) severely impacted while others (such as Arizona) were much less affected? Is there a way to find a middle ground between resuming public activities without putting huge numbers of people at risk?

The short answer is sort of. Because we lack an effective therapy for serious infections and because we do not yet have herd immunity, we must remain vigilant about our preventative practices. These practices primarily consist of avoiding large gatherings of people (more then 10-15) and continuing to wear masks while around strangers. If you have been vaccinated and you are in a small gathering with others who have also been vaccinated, then it is now considered safe to be unmasked when together. Six feet remains the recommended ideal social distancing although three feet is now being considered acceptable in schools. Be aware though children under age 12 are not currently considered to be major spreaders of Covid19, and this is possibly why three feet appears safe in schools.
To fully be safe we need to have the ability to identify and isolate those who are infected. Sports have provided a good model, with many infected asymptomatic athletes being identified because they are being tested on a continuing basis. This intense monitoring is not really feasible for the whole population yet applying it to areas where there are rising numbers of cases would make sense.

Finally, many people would like to travel again and are wondering if vaccinated why they are still being advised not to. With the variant strains we are unable to currently gauge how much risk a vaccinated individual may have. Remember that vaccines are designed to prevent a more serious case or death from Covid19. You can still be infected, and if you get infected with a strain that is not well protected by our current vaccines then you could spread it to others or even get ill yourself. I realize the frustration many feel with these recommendations yet in medicine caution is always the better part of valor and we must work with the data and evidence available to us.

Take care.

March 5, 2021 Covid update

With the approval of the Johnson and Johnson vaccine, the US now has 3 vaccines available raising the hope that everyone in the US could be immunized by mid-summer. This new vaccine differs from the Moderna and Pfizer vaccines in many ways and has certain advantages over them.

First off, it is a single shot rather then two. It is easier to transport and store, requiring only regular refrigeration rather than a freezer, and it can also be stored for longer.

It uses a different approach then the other two as well, utilizing an older method of using an inactivated virus to deliver the Covid spike protein, rather than a piece of RNA. Side effects though are similar with a sore arm the most likely reaction. However, just like with Moderna and Pfizer, headaches and flu like symptoms can occur for up to 48 hours after the vaccine.

Some perceive the Johnson and Johnson vaccine as less protective since in studies it was only shown to be effective at preventing symptomatic Covid19 infections 72% of the time (in the US) compared to 95% for the other two vaccines. This perception is inaccurate though. With regards to preventing someone from ending up in the ICU or dying from Covid19 all three vaccines show the same success. The difference in the efficacy numbers relates to the fact that the Johnson and Johnson vaccine was tested in areas of the world where there are more resistant variants. It is unlikely that the current formulations of the Pfizer and Moderna vaccines would show the same high effectiveness rate if they were to be retested in those areas of the world now.

As I have mentioned over the last several weeks the variant strains of Covid19 continue to remain a major concern, as they may reduce the protectiveness of the vaccines. At the moment, the most worrisome variants are the ones from Great Britain, South Africa and now Brazil. Currently, the British strain is the variant most isolated here in the US.

These variant strains represent genetic drift, which is the slow accumulation of mutations that ultimately result in a confirmational change to the virus. This change causes the virus to appear different to our immune systems (sort of like putting on a wig as a disguise) and can lead to reduced immunity. It does not necessarily lead to increased virulence or deadliness.

On the other hand, genetic shift occurs when two strains of the same virus combine to form a brand-new virus. These super mutants are often more deadly and may not even be protected against by existing vaccines. A super mutant consisting of the British variant and a California variant has been isolated by labs in California and Los Alamos New Mexico. For the moment, this super variant strain does not appear to be circulating in the population, yet if it ever does, we may be back to where we were when the pandemic began or even worse.

I have always been bothered by the fact that in the 6 hours between the signing of the Armistice ending World War I and the actual ceasefire, up to 10,000 soldiers were wounded or killed. Many of those casualties were avoidable. I cannot help but feel we are in a similar situation with Covid19. We are potentially seeing the beginning of the end of the pandemic, yet a very real danger still exists for infection and death. I do believe that in another six to eight weeks we will have a much clearer picture, yet for now please continue to remain vigilant and continue to practice social distancing and wear masks while in public.

Take care.

COVID 19 Update 2-26-21

Nationwide, and here in Arizona, the number of new Covid19 cases and deaths has been declining. While still at high numbers, Arizona is now back to where we were in mid-November, with the seven-day average of cases 1,530 and the seven-day average of number of deaths at 90. Overall, Arizona is now fifth in the nation in number of deaths per capita and fifteenth in number of cases, which is an improvement from January when Arizona was number one in both categories.

It is not entirely clear why the numbers are declining. For the moment, it is too early for vaccines to be making a big difference in the general population. However, for nursing home residents, there has been a dramatic decline in the number of deaths from Covid19 and vaccines are believed to be playing a role in this improvement.

There is great worry that people will become less careful as the number of cases decline, setting us up for another bad outbreak in the next two months. As I mentioned in my message last week, even if you are vaccinated you need to wear a mask and stay socially distanced if in public. As more people get immunized and more time progresses, this recommendation will be modified, yet people must remain vigilant for now.

Also last week I talked about the variant strains of Covid19 being isolated and the concern they could make vaccines less effective or even not protective at all. It is important to realize that so far the only data we have about the resistance of variant strains is based on in vitro or test tube studies. Concentrations of the variant strains are mixed with serum from people who have been immunized and the amount of virus incapacitated or eliminated by the serum is then measured. Realize that while helpful, these in vitro studies do not always reflect what goes on in the real (or in vivo) world of the body, and it is possible that the vaccines may be more beneficial then believed. Nevertheless, both Modena and Pfizer are working on a third dose of their respective vaccines to protect against the most worrisome variants. In addition, the Johnson and Johnson vaccine has been shown to be protective against some of the variants as well.

While vaccines will ultimately be the way Covid19 is controlled, effective therapies are being sought for mild, moderate, and severe cases. Unfortunately to date, we have been unsuccessful in finding a curative treatment. A lot of publicity has been given to several proposed remedies, starting with Plaquenil/hydroxychloroquine about 11 months ago (which was demonstrated to be useless in multiple well-designed studies).

Recent randomized controlled trials have been published looking at Pepcid/Famotidine and Vitamin C and Zinc as either preventative or curative therapies. The studies have not shown any improvement using these agents compared to taking nothing at all.

Vitamin D3 continues to be talked about as possibly preventative, yet currently there is no data supporting this. Indeed, we know that low Vitamin D levels are associated with a multitude of illnesses, and that Vitamin D may enhance innate and adaptive immunity. However, some (including myself) believe those low levels are felt more to be a marker of disease, or nutritional status, rather then the cause of the illness itself.

A Brazilian study published online this week In JAMA (the Journal of the American Medical Association) looked at a single high dose (200,000 units or 5000 mcg) of oral Vitamin D3 versus placebo for hospitalized Covid19 patients. The high dose vitamin D improved the blood levels of vitamin D yet did not result in shorter hospitalizations or better outcomes.

Time will tell if Vitamin D proves effective. If you are considering using Vitamin D, do not use more then 2000 units (or 50 mcg) a day (unless you are on a higher dose for Vitamin D deficiency). Excessive vitamin D can lead to liver damage and death.

Finally, two last items: first, mammograms should not be done until four weeks after the second Covid19 vaccine since the vaccines can cause lymph node enlargement on the side of the injection. This enlargement can be mistaken for a cancer and can lead to an unnecessary biopsy. Lastly, the office will be closed next Friday March 5, 2021 for training. Phones will not be answered, yet if you need something urgently or emergently contact me directly on my cell phone.

Take care and have a wonderful week.

2-19-21 Covid19 update

Now that more people are being immunized, I am getting more questions about what activities may be ok to do again. Patients are wondering if going to the gym or eating out can now be done without risk of infection. To answer that question, I need to elaborate on what is going on this week.

In Houston Texas, a small group of people were found with extremely high viral loads and relatively mild disease. This group subsequently infected many individuals supporting a current theory known as the 20/80 rule. It is believed that 20% (or less) of the population causes most infections, and consequently the continuation of the pandemic.

In this Houston group the current predominant strain (D614G) was isolated, yet it is believed that by the end of March or early April this strain will be surpassed by the UK/British variant strain B.1.1.7. Thankfully, the British variant remains sensitive to the Pfizer and Moderna vaccines.

However, there are additional variants which are not. The South African strain (B.1.351) is the most concerning, as that is spreading rapidly through the world and is less responsive to the Pfizer and Moderna vaccines (although they do offer some protection).

With more genomic sequencing of the virus, additional mutant strains are now being identified, and so far, seven additional variants unique to the US have been found. At this time, it is unclear how significant these US variants are, although one (from Southern California) has been isolated here in Arizona in addition to the British variant. So far, no cases caused by the South African variant have been identified in Arizona.

One hypothesized worry about vaccines is that someone immunized can still be an asymptomatic carrier of the virus and pass it on to someone else (remember the 20/80 rule). Variant strains not as well covered by the current vaccines could make this transmission more likely. Indeed, it is theoretically possible that an immunized individual could infect another immunized individual with a resistant strain.

So, even though someone may be immunized, they are not necessarily completely protected. Hence, the continuing advice of staying socially distanced and wearing masks when around others. Eventually, when over 70% of the population is either immunized or has natural immunity, these concerns will most likely ease, yet it will be at least another 3-4 months before that occurs.

Therefore, it is ok to go to a gym if you continue to wear a mask when there with others. Eating in a restaurant is a bit trickier, since obviously you need to remain unmasked, yet if done in a larger room with few people this is probably ok. Eating outdoors or a similar open-air environment would be preferable. Getting together with family who have all been immunized or have recovered from an infection is also probably ok yet remember that most of the spread of the last few months occurred in small family get togethers.

The most frustrating aspect of Covid is the unknown. We continue to understand the virus better as time goes on, so it is likely that some of what we believe today may be disproven in the future. Nonetheless, we are limited by what we know and need to advise accordingly in order to bring this pandemic to a quicker end.

I will be back next week with another update. Take care.

Covid19 update Feb 5, 2021

The number of confirmed COVID-19 cases continues to fall here in Arizona. A few weeks ago, Arizona led the nation in the per capita rate of infection. Currently, we are now fourth in the nation with our seven-day average of new cases at 4,080 per day and the number of deaths averaging 133 a day.

While this is encouraging news, these numbers remain extremely high, and some experts maintain that the actual number of cases is much higher since many people still do not get tested if they feel ill or may not feel ill at all. Regardless, the virus is still a very real and present danger. Staying at home as much as possible, wearing a KN95 or N95 mask when going out, and staying 6 feet apart from others while out are still the best way to prevent an infection even if you have received a vaccination.

Mutations or variants of the COVID-19 vaccine continue to be identified and remain worrisome. As noted in my last presentation, the British/UK variant is much more infectious and has been identified here in Arizona as well as other states. Thankfully, this variant does appear sensitive to the vaccines currently in use worldwide. However, the current vaccines may not protect as well against variants from South Africa and Brazil, so the race is on to immunize as many people as possible before these variants become more prevalent.

Unfortunately, vaccine supply continues to be limited both here in Arizona and nationwide. Some of this shortage is due to logistics and distribution of the vaccines from the manufacturers yet most of the problem remains not having enough vaccine for everyone at this time.

A good milestone was achieved this week worldwide, with the number of people receiving at least one dose of vaccine (approx. 104.9 million) now higher than the number of people with confirmed cases of COVID-19 (104.1 million). According to the CDC, in the US, 35 million people have been vaccinated versus 26.4 million confirmed cases, and in Arizona almost 574,000 people have received one dose of the vaccine which means to date, just under 8,000 people per 100,000 have gotten a vaccine dose.

Sadly, getting registered for a vaccine here in Arizona remains a major challenge. Even as pharmacies start to become sites for getting a COVID-19 vaccine, they, like the mass administration sites at Banner, TMC, Kino Sports Complex, and the Tucson Convention Center do not have any appointments available for the next several weeks. Similarly, the 24-hour sites in Phoenix are also booked up. Nevertheless, I encourage those of you with computer access to keep trying. Pima County has now opened registration to those aged 70 and up, and in Phoenix and other parts of the state, vaccines are being given to those 65 and older.

For those of you who do not have computer access and have difficulty getting thru on the phone lines, please contact the office to have my staff try to assist you. We have no special influence so be aware we may not be able to accomplish much at this time, yet at least we can try to help those who are not on the internet.

Finally, there are two to three additional vaccines moving closer to availability with the Johnson and Johnson one up for approval this month. If that occurs, then there is a fair chance that by the end of June about two-thirds of the country could be immunized against COVID-19.

Take Care,
Jeff Mayer, MD

Links for FDA Authorized KN95 masks

Here are two companies that are reputable mask sellers. The two options are the KN95 masks from China (which are FDA authorized) and the KF94 masks from South Korea. The FDA certification is important to assure these masks are protective. While FDA authorized masks may be available on Amazon or eBay, there are a lot of fake masks around so it can be unclear if you are truly getting a certified mask. Be aware there is a KF80 mask as well yet this is not as protective as the KF94 mask. I’ve also included a link to the FDA website regarding masks. Be aware the term respirators refers to these masks.
FDA Authorized KN95 masks
KF94 (Korean) masks

FDA FAQ regarding masks
FDA Fact sheet on masks. A little technical