If you have received a COVID-19 vaccine shot, you can help the Center for Disease Control record information about side effects, or their absence, through V-safe, an after vaccination health checker launched on Dec. 13. All you need is a smartphone.

During the first five and a half weeks of vaccine administration, two million people voluntarily enrolled in this monitoring system. Participants report on their health and side effects for up to one year.

According to data received from Martha Sharan of the CDC Feb. 5, 12,153,536 people have received one dose of Pfizer- BioNTech and 9,6989,497 have received one dose of Moderna. Reactogenicity (the inflammatory response to vaccination) has been found to be similar to other vaccines, but a bit higher in some cases, with both Pfizer and Moderna. These reactions/symptoms are fever, fatigue, headache, myalgia, chills, fever, swelling and joint pain. The CDC has yet to receive such reports after the second dose of the Moderna formula. According to the CDC, there are no safety concerns because the side effects are the same as in the clinical trials of both vaccines.

The CDC emphasized, the symptoms/reactions are a sign the vaccine is working and the immune system is doing its job responding to the vaccine.

Register for V-Safe at https://vsafe.cdc.gov. The information requested will be on your vaccination record card. After completing the information requests, the CDC will send text messages to your smartphone with survey links daily for the first week. This survey asks about participants’ health and how they are feeling. After the first week, texts will continue weekly for six weeks so the CDC can monitor participants’ progress in building immunity. Subsequent text message checks are at three, six and 12 months.

According to the CDC, v-safe uses information systems the CDC, FDA and other federal agencies manage, and the systems use strict security measures due to the sensitive data.

For live support if you have trouble participating, call 800-232-4636, Monday-Friday, 8 a.m. to 8 p.m. The ITY number is 1-888-232-6348. For more information, visit https://www.cdc.gov