Your questions about COVID-19 vaccines answered

A vial of the Pfizer-BioNTech COVID-19 vaccine
The Pfizer-BioNTech vaccine against COVID-19 requires two doses three weeks apart.
(Liam McBurney / Associated Press)

Healthcare workers and others have been receiving vaccinations against COVID-19 for about a month, a major turning point in the U.S., which has recorded more infections and deaths than any other country in the world. Naturally, we all have questions about these developments.

Times readers sent us 89 submissions over four days. By far, the most common question was some form of this one: When can I get the vaccine?

We can’t give you an exact date, but the short answer is that vaccines could be available to the general public in the spring or summer of 2021. Many of you wanted to know about vaccine safety and about the science behind the vaccine. There are sections below on those topics.



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Jump to questions and answers about:
Timeline and logistics | Safety | Vaccine science | Individual health


Timeline and logistics

Healthcare workers are first in line to be vaccinated in California. An expert panel has advised the Centers for Disease Control and Prevention that nursing home residents should be next in line, though each state will make its own decision. Los Angeles County plans to follow that recommendation, and then vaccinate essential workers and other high-risk groups. California has set phases and tiers to help people understand who is eligible. L.A. County is communicating which subsets are currently eligible on its public health department’s website.


Vaccine safety

Vaccines are safe. The COVID-19 vaccine from Pfizer and BioNTech that has been approved for emergency use was subject to well-established procedures to evaluate vaccine safety by scientists at the U.S. Food and Drug Administration and elsewhere. The same is true about the Moderna vaccine. California and other Western states have also endorsed the Pfizer vaccine’s safety. Early on in Britain’s first vaccinations, two people may have had allergic reactions, but they recovered.

The FDA has never approved or authorized a vaccine that uses mRNA (see the section on vaccine science below for more on mRNA) before. Nevertheless, Commissioner Stephen Hahn said the technology has been around long enough that regulators are “very comfortable” with the platform.



Vaccine science

Scientists had a head start in creating vaccines during this pandemic, based on earlier advances made against the SARS and MERS coronaviruses, which are relatives of the virus that has upended 2020.

BNT162b2, as the Pfizer-BioNTech vaccine is officially known, was developed in a matter of months thanks to a new method that uses a piece of the coronavirus’ genetic code rather than the virus itself. The Moderna vaccine works similarly.

Once the vaccine is injected into the body, the genetic payload — called messenger RNA, or mRNA — instructs cells to produce specific coronavirus proteins. The immune system responds by creating antibodies that are primed to attack the real coronavirus, said Dr. Bruce Walker, an immunology and infectious diseases researcher at Harvard and MIT.

“The process lasts in the body for about 36 hours,” Walker said. “Then the vaccine is degraded and essentially gone.” But the crucial antibodies remain.


Individual health

We aren’t doctors, so we can’t answer questions about specific circumstances. Your best course of action is to discuss your health and any concerns about vaccination with your doctor.