Covid-19: What side effects to expect from a vaccine shot? Will it be more painful than flu vaccine?

Researchers usually take years to develop a vaccine as they collate data over a period of time to ensure that there are no harmful side effects after taking the shot. However, the coronavirus disease (Covid-19) turned into a pandemic within weeks and claimed thousands of lives, prompting scientists to develop a vaccine within record time.

Russian President Vladimir Putin has already ordered mass immunisation against Covid-19 with Sputnik V vaccine to control the surge in virus-related deaths. Meanwhile, the United Kingdom has also approved a Covid-19 vaccine, developed by Pfizer Inc. and BioNTech SE, for emergency use. The government is expected to roll out the vaccine next week.

US biotech firms Pfizer and Moderna have submitted applications to the Food and Drug Administration (FDA) for emergency use authorisation as the United States continues to witness huge spike the Covid-19 cases and related deaths. Both companies have used new mRNA technology to develop the vaccines and have reported efficacy rate of around 95 per cent.

What side effects to expect from a Covid-19 vaccine shot?

While the companies have said that the vaccines are safe, many people still remain concerned about their side effects. The Data Monitoring Committee for the study of phase 3 trial of Pfizer’s vaccine has not reported any serious safety concerns related to the vaccine. It reported some cases of fatigue and headache after the volunteers received the second dose of the vaccine.

“The only Grade 3 (severe) solicited adverse events greater than or equal to 2% in frequency after the first or second dose was fatigue at 3.8% and headache at 2.0% following dose 2,” Pfizer said in a statement.

Moderna has also reported that the majority of adverse events were mild or moderate in severity. The first dose of the vaccine caused injection site pain in some of the volunteers and the second dose caused fatigue, pain, and redness at the injection site. The company said that these solicited adverse events were generally short-lived.

Dr Anthony Fauci, the US’ top infectious disease expert, on Monday told Facebook chief executive officer Mark Zuckerberg that the vaccine induces response and some people may feel an ache in the arm or get a fever. Dr Fauci, the director of the National Institute of Allergy and Infectious Diseases, said that “almost all of this goes away within 24 or at the most, 48 hours.”

“In some people, they don’t feel anything. Others feel an ache in the arm. Some may feel an ache in the arm and kind of a little chilly feeling, almost like you have a flu-like syndrome, and in a minority of people, they get a fever,” he said.