I’m vaccinated, but I still need a mask? Yes, maybe…


There is a small chance that the fully vaccinated against COVID-19 may become infected with some of the evolving variants. Variants are mutations of the coronavirus genetic code, which is a phenomenon that occurs in all viruses.

Rising cases of coronavirus throughout the world are currently creating concern. Currently, the variants are named by letters within the Greek alphabet and not by the country where they are first discovered. This makes identifying them to the general public less complicated and removes the stigma of identifying them by country of origin.

The United Kingdom coronavirus mutation is known as the alpha variant, while the delta variant was first seen in India. Most recently, the COVID-19 surge is largely driven by the delta variant and the delta plus variant. The delta plus variant is a result of an additional mutation of the spike protein seen on the original delta variant. 

As a virus mutates it may become more efficient in replicating, which in turn may infect a greater number of people. Overall, variants may:

  • spread more easily
  • be resistant to current treatments
  • cause greater illness, and
  • lower the effectiveness of current vaccines or natural immunity gained from prior Sars-Cov-2 infection.

Some countries such as Australia, South Africa, and Malaysia have returned to lockdown due to the delta variant. Twenty percent of all new COVID-19 cases are from the delta variant in the U.S., and this number may be doubling every two weeks. 

The delta variant differs in its presentation of predominant symptoms: headache, sore throat, runny nose, and fever. Unfortunately, the same symptoms can be seen with the common cold.  The delta variant symptoms are more severe than the original coronavirus, and it affects young people more commonly.

Coughing is seen later down the line, unlike with the initial COVID-19 variants where it was a very early, significant symptom.

Delta is 60% more infectious than the alpha strain and known to cause more severe disease. A study in Scotland found that the exposure to the delta variant was two times more likely to lead to hospitalization. The delta variant is also not as responsive to monoclonal antibodies or convalescent plasma as is the original Sars-Cov- 2 or its alpha variant.

 What can we do?

Consider wearing a mask:

  • indoors when in a crowded setting
  • around Immunocompromised people
  • around unvaccinated people, and
  • in areas with high COVID transmission rates.

As an example, Los Angeles Health Department officials are recommending wearing masks when indoors. Similarly, the World Health Organization (WHO) is recommending masks and social distancing for all when indoors, while the U.S.-based Centers for Disease Control and Prevention (CDC) is not recommending that at this time.

This is likely because two-thirds of the U.S. population is vaccinated with adequate protection from these new variants. The WHO has to make recommendations applicable to the rest of the world where vaccination rates are much lower than in the United States. Sadly, most other countries do not have access to the three very effective vaccines we possess.


All three predominant vaccines in the U.S. have excellent effectiveness in preventing severe disease from COVID-19. There is some question as to whether the J&J adenovirus-based vaccine is as effective against the variants as the two mRNA-based vaccines we have.

J&J may have less of an antibody response that stops infection, but the T cell response is still present. It is this T cell response that prevents an infection from spreading. Severe disease is then averted. 

Booster vaccines in the future

We may need additional vaccination in the future, but enough time has not transpired to know this, nor do we have that data yet. Luckily there is a small scientific study that indicates mRNA-based vaccines may provide years of protection as long as the virus doesn’t mutate significantly.

J&J recipients may need a booster, possibly with one of the mRNA vaccines. The CDC has not made an official statement, but European studies have demonstrated that mixing vaccines is likely safe.

As we progress into the future, the greater vaccination rates should lead to less severe disease and fewer people infected with COVID-19. There will be less chance for the virus to mutate into lethal variants. Taking other temporary measures such as masking and distancing should be considered if other variants evolve. That is a small price to pay for our well-being.

Sean J. Ennevor, M.D. graduated with a B.A.S. in biology and economics from Stanford University, and as a Dean’s Scholar from UCLA School of Medicine where he received his MD. He completed his medical residency and fellowship in anesthesiology at Yale University, where he was chief resident and on staff. He practiced medicine in the Twin Cities for over 14 years, and presently serves as an advisor and investor for medical technology companies throughout the country.