May 5, 2021 —
Q: How long will protection last following vaccination?
A. We do not know how long protection will last following vaccination but it will be critically important to measure long-term protection in the phase 3 trials and in other groups prioritized for early vaccination. We are still learning about the duration of protection following infection with COVID-19 and it is too early to tell how long protection will last.
Q. Can a vaccinated person still transmit the SARS-COV-2 virus that causes the COVID-19 disease?
A. Additional studies have shown that Pfizer-BioNTech and Moderna vaccines not only prevent people who are exposed to the virus from contracting COVID-19, but also prevent them from spreading the virus to others.
More data is currently being collected to provide definitive answers regarding infectiousness and transmissibility of COVID-19 by those who have been vaccinated. However, large studies have demonstrated that vaccinated persons have significantly fewer coronavirus infections, both asymptomatic (89.4%) and symptomatic (93.7%) based on nasal swab PCR tests, than found among unvaccinated persons.
The Centers for Disease Control and Prevention (CDC) recommends continuing to practice public health protective measures like washing your hands, wearing a mask, physical distancing, and frequently cleaning common areas.
Q. Will I still need to wear masks and practice physical distancing once a vaccine is available?
A. Yes. Both vaccines work to protect individuals from COVID-19 disease symptoms, but it is unknown at this time whether vaccinated people will still be able to transmit the virus as an asymptomatic infection. It is recommended by the Centers for Disease Control and Prevention (CDC) to continue to practice public health protective measures like washing your hands, wearing a mask and frequently cleaning common areas.
In accordance with the 21 January 2021 Executive Order on “Protecting the Federal Workforce and Requiring Mask-Wearing,” executive departments and agencies, including the Coast Guard, must ensure compliance with CDC guidelines with respect to wearing masks, maintaining physical distance, and other public health measures. This direction applies to on-duty or on-site Federal employees, on-site Federal contractors, and all persons in Federal buildings or on Federal lands.
Q: Can I still get sick with the COVID-19 disease once I have been vaccinated?
A: Yes, even though the vaccine is highly effective (has a high efficacy), it’s still possible for a vaccinated person to become ill. The protection provided by the vaccine is not immediate after receiving the second dose. Current information indicates it takes time for a person’s immune system to fully respond to the vaccine and produce antibodies. According to the Centers for Disease Control and Prevention (CDC), evidence from clinical trials indicates that the Pfizer vaccine reaches full potential, 95% efficacy, at least 7 days after the second dose. At the 95% effective rate, approximately 5% of those who receive both doses of the vaccine may still get the COVID-19 disease. Clinical trial data for the Moderna vaccine indicate that it reaches full potential, approximately 94% efficacy, at least 14 days after the second dose.
You can read more from the CDC about the different COVID-19 vaccines, including Pfizer and Moderna, at https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines.html.