Dr. Cardona explains, “‘Fully vaccinated’ means that you completed a COVID-19 vaccine series as recommended for the best protection against severe complications such as hospitalizations and/or death. No vaccine offers 100% protection against illness, yet it does give you a better chance to fight off the infectious consequences of being exposed to the SARS-CoV2 virus.”
About half of the U.S. population is fully vaccinated. Vaccinated people can spread COVID-19 to others and need to do several things to stay safe. Infectious disease specialist Lyssette Cardona, MD, answers those questions and covers why vaccination is still one of our best weapons in the fight against COVID-19.
Dr. Cardona says that the ability to transmit COVID-19 is possible, but may occur at a lower rate. Contracting COVID-19 could also be a reality for people who don’t have a good immune response to vaccines. “The elderly, those with immune or chronic health conditions or those with underlying health disorders may not have the best protective response to vaccines, such as the COVID-19 vaccines. We are still collecting data and doing ongoing research about the vaccine responses in these vulnerable populations.” “There are reported cases of illness and/or exposure after the vaccines, but the complications of the disease for those not vaccinated yet has been of greater magnitude.”
On June 7, the CDC issued a press release about their study of the effectiveness of vaccines in fully vaccinated people. The study found that the mRNA COVID-19 vaccines authorized by the Food and Drug Administration (FDA) ( Pfizer-BioNTech’s and Moderna’s) reduced the risk of infection by 91% for fully vaccinated people. The study also is among the first to show that mRNA vaccination benefits people who get COVID-19 despite being fully vaccinated (14 or more days after dose two) or partially vaccinated (14 or more days after dose one to 13 days after dose two).
The results of this study also suggest that fully or partially vaccinated people who become infected with COVID-19 may be less likely to spread the virus. With fully or partially vaccinated study participants, the virus was 40% less detectable in their noses. It was also detected in six fewer days (i.e., viral shedding) as compared to those who weren’t vaccinated when they became infected.
People who were partially or fully vaccinated were 66% less likely to test positive for the SARS-CoV-2 infection for more than one week in comparison to those who were unvaccinated. The CDC adds that while these indicators are not a direct measure of a person’s ability to spread the virus, they have been associated with a reduced spread of other viruses like varicella (chickenpox) and influenza (flu).
Dr. Cardona stresses that fully vaccinated people still need to be careful as everything opens up again. “Virus transmission may still occur from those who are infected and asymptomatic, or ill without knowing it, especially in crowded areas with a lack of physical distancing, respiratory precautions and hand washing. Other factors to consider are ongoing community transmission (positivity of testing) and immunization rates.