The vaccine for the coronavirus disease 2019 (Covid-19) has so far caused no severe side effects among most of those who received it in the United States.

According to data released Friday by the US Centers for Disease Control and Prevention (CDC), People who receive vaccine for the coronavirus disease 2019 (Covid-19) report shot-related side effects at a rate of roughly one for every 2,000 doses, with more than 90 percent classified as “non-serious.”

Headaches were the most common side effect, followed by fatigue and dizziness, the data showed.

Although 113 deaths were reported following receipt of the vaccine, none were found to be related to the shot, the agency said. About 65 percent were among residents of nursing homes.

The findings are based on the first 13.8 million doses of either the Pfizer-BioNTech or Moderna vaccines administered in the United States between Dec. 14 and Jan. 13, according to the CDC.

Fewer than 7,000 side effects were reported with both vaccines, which require two doses and were approved for use in mid-December.

“Healthcare providers and vaccine recipients can be reassured about the safety of Pfizer-BioNTech and Moderna COVID-19 vaccines,” the CDC researchers wrote.

“Counseling vaccine recipients to expect [non-serious] reactions might ease concerns and encourage completion of the two-dose vaccination series,” they said.

Less than 10 percent of the side effects reported were considered serious or life-threatening, a figure that includes fewer than 100 cases of anaphylaxis, or a severe allergic reaction, reported with both vaccines, according to the CDC.

Of the non-serious side effects, 22 percent involved headaches, 17 percent were cases of fatigue and 17 percent included reports of dizziness, the CDC said.

MORE VALIDATION FROM FOLLOW-UP SURVEY

A follow-up survey of more than 1.6 million vaccine recipients revealed that more than 70 percent experienced injection-site pain following administration of either the Pfizer-BioNTech or Moderna shots, the data showed.

Roughly one-third of recipients reported fever and 30 percent indicated they suffered headaches within seven days of receiving either vaccine, the CDC said.

Nearly 80 percent of the survey respondents said they experienced injection-site pain after receiving their second dose of the Pfizer-BioNTech vaccine, while 54 percent reorted fatigue, 47 percent had muscle pain and 43 percent suffered from headaches.

These numbers were much higher following receipt of the second dose of the vaccine than the first, but all were considered non-serious, the CDC said.

Information on second-dose side effects for the Moderna vaccine was not available, as they had yet to be administered prior to the Jan. 13 close of the study period, according to the agency.

However, rates of side effects following administration of the first dose were similar for both vaccines, the data showed.

Doses of the Moderna vaccine are administered 28 days apart and the product was approved for use on Dec. 18, the agency said.

The two doses of the Pfizer-BioNTech vaccine, which was approved on Dec. 11, are given 21 days apart.