The CDC’s emergency use authorization of two COVID-19 vaccines in December 2020 marked a turning point in the pandemic. But that does not mean individuals should stop taking steps to prevent the spread of the virus. The CDC and other health officials recommend that all people, including individuals who have received the COVID-19 vaccine, continue the primary recommendations of social distancing, hand washing, wearing a mask, and staying home when feeling sick.
There are several reasons health officials make the argument is favor of “steady as she goes” with regard to these practices. These include:
- The vaccines are proven for prevention, not transmission.
The current vaccines available in the United States (Moderna and Pfizer, as of January 2021) were tested for efficacy of preventing COVID-19, not for reducing transmission of the virus. Among people who have been vaccinated, when they are exposed to the virus, it will make its way to and reside/proliferate in the mucous membranes of their respiratory tracts. While the body marshals its immune response, they are still capable of spreading the virus to those not yet vaccinated and potentially causing infection among them by coughing, sneezing, talking and breathing. We anticipate this will be at lower level than if they had not been vaccinated but we don’t yet know by how much. - Vaccine availability is limited.
Older and vulnerable people and frontline healthcare workers are currently being vaccinated as younger people wait their turn, possibly until summer 2021 or beyond. While these younger members of our population are at lower risk of death, they may still be at risk of serious consequences resulting from infection. In the United Kingdom, 43 percent of admissions to the intensive care unit since September 2020 have been among those aged less than 60, and 20 percent less than 50. - We have a long way to go before we reach herd immunity.
Generous estimates of those already immune (vaccinated and/or previously infected and recovered) are less than 20 percent of the population, so we have a long way to go before achieving herd immunity, when more than 65 percent of the population has been vaccinated. Without maintaining public health guidelines, the uncontrolled transmissions would result in continued waves of infection inundating the hospital systems throughout the U.S. for months to come. - We need protection against emerging COVID-19 variants.
A further risk of uncontrolled community exposures is promoting “human petri dishes,” that is providing the opportunity for variants to rapidly evolve and potentially rendering currently available vaccines less effective. Variants of concern already have been identified in the UK, South Africa and Brazil. The South African variant is particularly concerning because studies recently released suggest it is “less susceptible to the antibodies created by natural infection and by vaccines made by Pfizer-BioNTech and Moderna.” Undoubtably variants are currently circulating in the U.S., however the United States lags far behind in sequencing a reasonable sample of the millions of infections that have occurred within its borders.
While the efficacy of these two vaccines is impressive at approximately 95%, this is not perfect. On a population level, this still represents a significant level of potential harm and equates to at least 50,000 people becoming ill for every 1 million vaccinated and exposed. Other vaccines in use elsewhere are less efficacious resulting in proportionally greater illness and harm. Consequently, we must continue to follow public health guidelines and maintain our efforts to socially distance, to perform hand hygiene and to wear our PPE as recommended.