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The Covid-19 virus continues to ravage communities and spread around the world, especially in countries that have been unwilling or unable to follow common sense and effective public health measures. Despite being one of the wealthiest nations on the planet, the United States has led the world in new cases and deaths since April 2020, with rapidly increasing infections and death rates in recent weeks. After all that we have learned about the virus, right now there are more new cases, hospitalizations, and deaths than ever over the past year.

The rare, good news has been that several vaccines are on the way, and because the infection and death rates have been so exceedingly high, the clinical trials using the vaccines have yielded positive results in an extremely short period of time.

Over the last 12 months, we have learned that Covid-19 infections have hit the elderly and those with heart and lung disease the hardest, yet it has also killed young people, people who are healthy, and those who have chronic disease in often unpredictable ways. With improvements in therapy for hospitalized patients over the last 6-9 months, death rates have decreased from 3-4% of new reported cases to 1.5-2% of cases, an important but limited improvement, making a vaccine essential.

The Pfizer Covid-19 vaccine, called BNT162b2, as well as Moderna’s Covid-19 vaccine, called mRNA-1273, have made front-page news for the last few weeks as they represent a bright light at the end of what has been a long dark tunnel.

These new vaccines are made of a piece of modified RNA (virus genetic material) that encodes a version of the SARS-CoV-2 spike protein, a novel concept in vaccine development. As a protein, the vaccine cannot cause an infection, but can boost immunity and protect us from becoming sick.

Experience with previous coronaviruses (SARS in 2002 and the more deadly MERS in 2012) failed to produce an effective vaccine. This makes the recent publicity about the latest vaccine studies welcome news.

Just this week, the actual Pfizer vaccine results have been published in the New England Journal of Medicine for all to review, and December 12th the FDA advisors recommended authorization of the vaccine for emergency use. Although this remains an ongoing study with results that are not yet final, the data thus far is highly encouraging. You can read the article for free with this link: https://www.nejm.org/doi/full/10.1056/NEJMoa2034577?query=RP. The Moderna study results will likely be published and available very soon.

Highlights of Pfizer Vaccine Study Results

From the results published to date, findings show that the vaccine reduces infection rates by about 95%–truly amazing! In the primary analysis with over 40,000 subjects, only 8 cases of Covid-19 were seen in the vaccine group, as compared with 162 in the placebo group. These same results appear to be true for both the Pfizer and the Moderna vaccines, with both vaccines produced in a similar way. Thus far, subjects who were either young or old, black or white, healthy or with chronic health problems have shown similar reductions in infection rates—more good news.

In the clinical trial published this week, 21,720 participants received the BNT162b2 vaccine and 21,728 received a placebo. The Moderna study will also share results from a similar large sample size, helping to reveal any safety concerns associated with the vaccine use. Both Pfizer vaccine groups received two injections spaced 21 days apart, the Moderna vaccine also used two injections 4 weeks apart. Persons with obesity or other coexisting conditions were well represented, as well as many different ethnic communities, and more than 40% of participants were older than 55 years of age.

One important limitation of this study is that to date, the Pfizer vaccine findings represent only 2 months of safety data after the second vaccine was given. Important to know is that the results presented are only initial findings and part of an ongoing study.

To me, two months does not initially sound like much time for a clinical study to determine safety, yet fortunately, from hundreds of previous vaccine studies, we know that most serious side effects (such as a heart attack or neurological injury) occur within the first couple of months. Reassuring is that in this study so far, the vaccine subjects have had less serious events occur than the placebo subjects. However, out of 21,000 vaccinated subjects so far with published results, there were 4 cases of Bell’s palsy reported, which is often a temporary weakness in a facial nerve, which represents 1 event per 5,000 people vaccinated, A 0.02% risk.

The common side effects reported have been a reaction to the vaccine at the local injection site with soreness and redness, fatigue, and headache over the first 24-48 hours, and more rarely fever, which is typical for many vaccines. After the second vaccine, about 25% more vaccine subjects had these reported common side effects compared to the placebo group. These side effects were more frequent after the second dosage than the first.

If you think about it, I believe a 25% increased chance of mild arm soreness and cold symptoms for 1-2 days is well worth the 95% protection I would get from a potentially life-threatening Covid-19 infection that could impact me or someone dear that I love!

Does the Vaccine Prevent Severe Infections?

The critical and most important question, “Does this new vaccine prevent severe infections?” has not been fully answered yet. Thus far, the data again is reassuring. Ten severe Covid infections have occurred in both Pfizer study groups thus far, 1 in the vaccine group and 9 in the placebo group, which appears to be a nearly 90% reduction in severe cases with the vaccine.

Yet, this is not enough information to draw any final conclusions on severe infection rates and researchers will have to continue to collect data to answer this critical question. The Moderna results have not yet been published, but their severe infection rate has been reported to show similar dramatic reductions in the vaccinated group.

Who Should Get the Vaccine Now?

The vaccine is already being offered to people in the United Kingdom and in Canada.

The FDA has approved the Pfizer vaccine for emergency use, and assuming approval for the Moderna vaccine as well next week, in December 2020, 20 million doses from Pfizer and 20 million doses from Moderna will be available almost immediately, and as two shots are needed for each person, this will provide a vaccination for 20 million people in the US. Other countries will follow soon.

The CDC has recommended that the following two groups should be the first to get vaccinated:

  1. Health care workers (people at high risk for exposure and who are essential to treating new cases which are skyrocketing)
  2. The elderly with co-existing health disease (especially those living in nursing homes and those who receive medical assistance in retirement homes) that make them high risk for severe infections and death if they become infected.

Health care works and the elderly with co-existing health problems will likely use up the 40 million doses that are available initially.

In January 2021, another 50-100 million doses will be available for those the CDC believes are at high risk of infection, high risk of severe infections, and/or are essential workers, including:

  • School teachers and staff
  • Police and other emergency workers (fire departments, medics, etc)
  • Public transport drivers
  • Daycare workers
  • People over age 65-75 (age cut off to be determined)
  • People who are not elderly but have health conditions that increase their risk for severe complications if they become infected, including people with diabetes and heart disease.

Based upon the information available at this time, I am hopeful and optimistic that by the time the vaccine is available to the general public in February or March 2021, far more data will confirm its safety.

The bottom line is that the new Covid-19 vaccines being produced by Pfizer (as well as a similar vaccine created by Moderna) appear to have more benefit than risk!

Who Should Wait a Few Months or Longer Before Getting the Vaccine?

Children, pregnant women, and immunocompromised people have not been included in studies thus far and should wait until the vaccine is proven to be safe for them. I anticipate a vaccine will be studied in children within the next year, and pregnant women and immunocompromised people will likely be included in future studies as well.

For now, everyone, but especially children, pregnant women, and immunocompromised people should practice public health prevention measures (mask-wearing and social distancing) and hope that as many people as possible are vaccinated as soon as possible to protect them via herd immunity. If you fall into one of these unstudied groups, your unique situation will determine your risk and benefit with the vaccine and the best advice would be to talk to your physician who knows you personally.

Initial experience from the ongoing vaccination program in the United Kingdom with people who have a history of severe anaphylactic reactions (Anaphylaxis, which is a severe and rapidly progressive allergic reaction; people with this condition use an Epi-Pen when they have a life-threatening reaction to bee stings, peanut allergies, shellfish allergies, etc) suggests that they are at increased risk for a severe allergic reaction to the vaccine as well. If you have a history of anaphylactic reactions, check with your physician before getting the vaccine.

What Else Do We Need to Do Besides Get the Vaccine?

Until 80-90% of the population has developed immunity to Covid-19, infections will continue to ravage our economy and to kill people on a large scale. Likely 10% of people have already been infected and have developed some immunity, so until at least 70% of us have been vaccinated, the new infection rates will remain uncontrolled.

For the near future, we still need to:

  1. Wear masks whenever we leave our homes,
  2. Social distance,
  3. Avoid crowds and social gatherings (especially indoors), and
  4. Practice common sense measures like washing hands and using hand sanitizer when we touch anything in a public setting.

If we want to avoid unnecessary deaths and suffering, prevent shutdowns that harm our economy, and help get people back to work, following each of these four steps remains essential.

What Unknown Information Do We Need to Watch For?

Thus far, only about 20,000 people have received the Pfizer vaccine, and about another 20,000 people have received the Moderna vaccine, with only 2 months of safety information on the vaccine, yet what rare but serious side effects might occur long term? The truth is that we do not yet know.

As an example, the influenza vaccine appears to cause Guillain Barré Syndrome once in every 500,000 people vaccinated, with clearly more benefit than harm, yet while there should be more benefit than risk, there are always rare hazards to any vaccination program. Similar rare side effects are likely to occur with this new Covid-19 vaccine as well.

We also do not know how effective 1 injection instead of 2 injections 3-4 weeks apart will be. For now, everyone who gets the first shot should plan to get the second injection, unless they develop a rare adverse reaction to the first shot.

Will the vaccine prevent asymptomatic infections and reduce the spread of infections? We do not yet know the answer to this question, but studies will collect antibody response data soon and this information will become available. The risk is that the vaccine reduces all symptoms and leaves people contagious to spread the disease. Until this is clear, everyone who gets the vaccine needs to wear a mask and practice social distancing!  I am optimistic that the vaccine will prevent asymptomatic carriers, but this needs to be confirmed, not just assumed.

How Long will the Vaccine Be Effective?

Many scientists expect the Covid-19 virus to mutate over time and predict that we may need annual Covid-19 vaccines, like we do with the annual new influenza vaccine. For now, we hope that this vaccine is effective for at least 1 year, hopefully longer. Time will tell.

What Am I Going to Do?

I am in my mid-60’s, so I plan to get this vaccine as soon as it becomes available to me.

I hope this blog gives you the information you need to decide what to do as the vaccine becomes available.

Please be safe and follow all the public health guidelines for at least the next several months.


I wish you the best of health!

Steven Masley, MD, FAHA, FACN, CNS


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