You Asked: Why Are There Multiple COVID Vaccines?
As states distribute the COVID-19 vaccines, there are still plenty of questions about the process— and the vaccines. Here are some questions we received recently from community and audience members through our texting groups, the Midwest Checkup and the Indiana Two-Way. Answers come with help from health experts at.
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There is a slim chance that a vaccinated individual might still come down with COVID-19. The two most widely distributed vaccines--Moderna and Pfizer-BioNTech--are reported to have about 95% efficacy. That means about 5% of vaccinated people are still likely to contract COVID-19. While they may still contract COVID, however, their chance of hospitalization or death is still lower than someone who has not received the vaccine.
Additionally, it takes a week or two after the second dose--depending on which vaccine you receive--to reach the maximum immunity. But during that week or two, an individual still runs a chance of contracting COVID-19.
Where can I find information on adverse reactions from the vaccines? How are they being reported and made public?
Here’s how medical professionals at Meedan explain the issue: Results from the clinical studies are published and publicly available. One platform that consolidates the results is the COVID-19 Real-Time Learning Network, which is made available thanks to a collaboration between the U.S. Centers for Disease Control and Prevention and the Infectious Diseases Society of America.
Additionally, now that COVID-19 vaccine candidates have been given to millions of people around the world, more data is becoming available from countries that are monitoring the vaccine distribution and collecting information. For example, in the United States, adverse reactions can be reported by providers of the COVID-19 vaccines, as well as by recipients on the national Vaccine Adverse Event Reporting System online platform. This reporting system is part of the many expanded vaccine safety monitoring systems that have been developed.
Are the manufacturers making any adjustments to the vaccines? If the manufacturers make adjustments, what is the process for testing the tweaked vaccine for safety?
Here's how medical professionals at Meedan explain the issue: Pfizer-BioNTEch and Moderna vaccines are made using mRNA, which is like a genetic software code that can be updated relatively easily and quickly. Tweaking the vaccine can be done in a couple of days, but updated vaccine trials might require more time. The FDA’s testing process and policy for the new booster shots is not yet known, but is expected to be publicized soon. Some experts suggest that the end result may look similar to the FDA’s process for the flu vaccine, which changes every year but does not go through full-scale clinical trial phases every time an adjustment is made.
The United States has several reporting mechanisms for monitoring long-term vaccine side effects. They include:
- (VAERS): This system allows people to report possible side effects or health problems that happen after vaccination. From there, theVaccine Safety Datalink(VSD) helps discover whether those problems are actually related to vaccination
- The Post-Licensure Rapid Immunization Safety Monitoring(PRISM) system is part of the FDA’s Sentinel Initiative, which monitors medical products after they’re licensed for use. Using a database of health insurance claims, it keeps an eye out for possible safety issues for licensed vaccines.
- The Clinical Immunization Safety Assessment(CISA) Project, a national network of vaccine safety experts.
The Centers for Disease Controland Preventionalso recently releasedV-Safe, a smartphone-based tool that checks in with people after they receive a COVID-19 vaccine to track any potential side effects.
There are multiple vaccines, in part, to combat the global scale of the pandemic. It’s simply too big for one pharmaceutical company to produce enough vaccines to meet the demand. Additionally, wealthy countries have already pre-purchased millions of vaccines directly from their distributors, leaving other countries to wait for supplies to become available. Having more vaccines means having more supply to reach more people, more quickly.
Because Pfizer and Moderna’s mRNA vaccines have strict refrigeration needs, they are not always feasible for countries with less infrastructure and communities located far from urban centers. Other vaccines may have less demanding needs, making them more accessible for such communities.
You may have been reading about polyethylene glycol (PEG). Polyethylene is a type of thermoplastic, and polyethylene glycol is a lipid nanoparticle (a very small fat). PEG is used as a thickener, moisture carrier, and/or solvent in products like toothpaste and shampoo and medical products like laxatives and biopharmaceuticals.
In the Moderna and Pfizer-BioNTech vaccines, which are mRNA vaccines, the lipids protect the mRNA as it travels through the body and into cells. Once the mRNA reaches the cells, the lipids dissolve and exit the body.
This is the first time PEG has been used in an approved vaccine, and some scientists have speculated that PEG may be a factor in some vaccine recipients’ allergy-like reactions. However, those speculations have not been confirmed and such reactions have been rare thus far.
This story was produced by, a news collaborative covering public health.
Side Effects, WFYI and Indiana Public Broadcasting are asking Americans about health issues, as part of . The public media initiative, funded by the Corporation for Public Broadcasting, uses community engagement to inform and strengthen local, regional and national journalism. Follow on Twitter at @amplified2020.
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