Health experts answer your questions about COVID-19 vaccines

NEW YORK (Reuters): An unprecedented COVID-19 vaccine campaign is underway with tens of millions now inoculated in the U.S. and around the world. Dozens of vaccine candidates are still in the pipeline, bringing hope for an end to a global pandemic.

As part of our #AskReuters Twitter chat series, Reuters invited a group of healthcare experts to discuss what you should know before getting your shot.

Below are edited highlights.

How do the various vaccines reduce the risk of COVID-19 and its complications? How long will they provide immunity?

“COVID-19 vaccines reduce complications by inducing the immune system to generate antibodies and T-cells that stop the virus from causing damage. The duration of immunity isn’t known, but I suspect longer than one year.”

— Amesh Adalja, senior scholar at The Johns Hopkins Center for Health Security

Are COVID-19 vaccines safe and effective for people with serious diseases, such as cancer?

“Everyone with questions about whether the vaccine is right for them should be talking to their healthcare provider. Generally, the vaccines have been shown to be very safe, and we know that COVID is not, especially for people at high risk.”

— Heather Pierce, JD, MPH, senior director and regulatory counsel at Association of American Medical Colleges

What are the expected side effects of a COVID-19 vaccination?

“Side effects include pain at injection site, tiredness, headache, muscle pain, chills, joint pain, swollen lymph nodes in the injection arm, nausea and vomiting and fever. When I got the first dose of the Moderna vaccine, I felt like I got punched in the shoulder for about 24 hours.”

— Dr. Joseph Petrosino, director of molecular virology and microbiology at Baylor College of Medicine

Will emerging coronavirus variants, such as those first seen in the U.K. and South Africa, affect vaccine efficacy?

“While the current vaccines look to protect against new variants, one consequence is that the more rapid spread of these variants necessitates faster vaccine roll out to limit the extent of subsequent waves of infection in spring and summer of 2021.”

— Josh Schiffer, professor at Fred Hutchinson Cancer Research Center

When do you estimate the United States will achieve herd immunity? What about globally?

“There are big problems for global herd immunity — even if the U.S. reaches wide coverage, because of vaccines being hoarded by rich countries, much of the world won’t. Seventy countries will only be able to vaccinate one in 10 people this year. Without change this means a continuing pandemic.”

— Matthew Kavanagh, assistant professor of global health and visiting professor of Law at Georgetown University; director of global health policy & politics initiative at O’Neill Institute

Can you discuss the importance of vaccine access, particularly in lower-income countries?

“COVID-19 vaccine access for everyone across the globe is critically important. It is our moral and ethical responsibility to make sure that this happens. As many have stated throughout this pandemic, we are not safe until the entire world is safe.”

— Dr. Krutika Kuppalli, infectious disease researcher

What do we know about the vaccine’s effects on pregnancy and reproductive health?

“Several agencies recommend vaccines should not be withheld from pregnant or lactating individuals who otherwise meet criteria for vaccination. Talk to your provider if you have any questions or concerns. As a breastfeeding mom, I got vaccinated.”

— Dr. Syra Madad, senior director, special pathogens at New York City Health & Hospitals

What gives you hope now?

“I actually cried when I saw the Pfizer vaccine data. This has been a hard year for all of us, but knowing that this disease is preventable and will be prevented took a weight off my shoulders.”

— Joshua Wolf, infectious disease physician at St. Jude Children’s Research Hospital