COVID-19 Immunology

What we know about COVID-19 immunity

While much remains unknown about COVID-19 immunity, a renowned DO immunologist shares the best information we have at this time.


As the editor-in-chief of a peer-reviewed medical journal, allergist/immunologist Massoud Mahmoudi, DO, PhD, has seen firsthand research, review papers and case reports from all over the world about COVID-19 since the pandemic started. And while the international medical community is working around the clock to better understand this virus, many important details remain unknown at this point, he says.

“We know the virus’s sequence, how to make antibodies, and we know a good amount about its transmission, though we probably need to learn a little more about that,” Dr. Mahmoudi said. “We don’t know why or if people really get re-infected or what the proper treatment is. Overall, we have a lot to learn.”

Since COVID-19 started, The DO has been speaking with osteopathic physicians about their experiences during the pandemic. If you are a physician and would like to be featured in an interview as we continue our COVID-19 coverage, please email

This week we spoke with Dr. Mahmoudi, president of the American Osteopathic College of Allergy and Immunology and editor-in-chief of Springer Nature Comprehensive Clinical Medicine, who is based in the Bay Area. In this edited Q&A, he discusses the current state of COVID-19 research and his cautiously optimistic outlook on the possible timeline for a vaccine.

As what we know about this virus continues to develop, where are you getting your information?

In my role for Springer Nature, I get information from all over the world. I’m reading a lot of COVID-19 disease-related material before it’s published, and review papers in immunology, virology, microbiology and other fields. I’m editing these papers and deciding what to do with them.

For my personal knowledge, I use UpToDate and PubMed in my research, and also, I’m always keeping up with the CDC’s guidelines, and following news as close to the original source as I can.

What have you learned that surprised you the most, thus far?

A lot of what I’m learning is surprising. There are seven types of COVID viruses, and many of them just affect the upper respiratory tract. But three of them, including SARS-Cov-2, affect the lower respiratory tract. We’re learning more about the SARS group of viruses in general, but the pathogenicity [the ability to harm the host] and ease of transmission of this virus are very unusual. People have been underestimating both of those things.

The pathogenicity is so rapid and so strong, and that’s what I’m learning more about. This virus can cause deep and long-lasting damage. Compared to the flu, COVID-19’s transmission is a lot faster.

What are your thoughts on antibody testing?

Bloodwork antibody testing tests two different antibodies: IgM and IgG. IgM shows if you currently are infected, while IgG shows if you had it in the past. But antibody testing is still more on the experimental side. It’s not really validated in a way that is useful for most people, but it gives researchers an idea as we attempt to find out if you are immune once you have had COVID-19.

If you’re really curious to know if you have the virus, you’d need to go get the RT-PCR (real time polymerase chain reaction) testing done, with a nasalpharyngeal swab. That is not totally accurate either, but it is the best test we have right now.

There have been some anecdotal reports about re-infections. What’s your take on these?

The people who have recovered, if you go and check their RNA, they may still show some of the virus. There are anecdotal reports of re-infection, but because these numbers are so low and so rare, we don’t know that much. Did they really get re-infected and go through the whole process again? Or are the later reactions to the virus milder? We don’t have an answer for why any of that happens yet.

How do you feel about the state of COVID-19 vaccine development?

Personally I’m very optimistic and hoping we’ll have one by the end of the year, but if we don’t, I won’t be surprised, because the Ebola vaccine just came out six months ago after many years of testing. More people are paying attention and putting in effort now because this is a pandemic.

I’m hearing from the CDC and others that vaccine developers are pushing harder and using research from multiple collaborating centers. It’s definitely a faster process than we’ve ever had before.

But, even if we have a vaccine, we don’t know how long the antibodies last. Suppose we get a vaccine in five months, and then we don’t know if it will help you for a year, six months, three months, or five years. We need to know a little bit more, and the sample size for any time-based data we have is quite small.

In the meantime, what do you think the best treatment options are?

For now, until we have a fully proven treatment drug, I’m seeing an emphasis on supportive care. That means care for fever, or providing oxygen, antivirals (like remdesivir) and antibiotics, whatever is needed. A lot of those with severe symptoms develop pneumonia, so treating that with supportive care is what we can do right now.

Related reading:

OB-GYN DOs talk about labor, delivery and prenatal care during COVID-19

COVID-19 updates: DO starts volunteer mental health support line for fellow physicians


  1. Ryan Shilian, D.O.

    With so much unknown and controversy about this pandemic it is refreshing to have insights from someone who has access to studies before they are published. Dr. Mahmoudi is like a messenger from the future. His knowledge of yet-to-be-published studies gives his opinion and insight considerable weight.

    It is so good for readers to hear from an expert of such caliber that SARS-Cov-2 is capable of causing lasting damage; that our current antibody testing is not very accurate; and that a vaccine may not necessarily provide instant or sustainable immunity.

Leave a comment Please see our comment policy