Moderna reports significantly higher risk of common side effects

• 5,052 vaccine recipients suffered a "health impact event" as of Dec. 19
• CDC defines "health impact event" as one that renders a patient "unable to perform normal daily activities, unable to work, required care from doctor or health care professional"
• That's a rate of about 2.3% of vaccine recipients
• CDC says a severe allergic reaction, anaphylaxis, was reported in 6 patients
• Both vaccines are effective at reducing the risk of symptomatic COVID-19 for at least 14 days (Moderna) or more than two months (Pfizer-BioNTech)
• It's impossible to know how effective the vaccines are beyond the number of days they've been given to humans. It's also impossible to know this soon what are the potential long term side effects, if any.

CDC emphasizes that it believes both of the COVID-19 vaccines approved for emergency use are safe and effective.

The agency is keeping a close eye out for adverse events.

The agency's "V-safe active surveillance program," which allows for patients to voluntarily, directly report adverse events outside of the normal VAERS (Vaccine Adverse Event Reporting System), reports that a total of 215,362 people had received their first dose of vaccine as of December 18.

Of that number, 5,052 or 2.3% were reported to have an unspecified "health impact event" defined by CDC as serious enough that they were "unable to perform normal daily activities, unable to work, required care from doctor or health care professional."

The V-safe surveillance program will help identify as-yet unidentified side effects that won't be seen until a much larger number of people have taken the vaccine. It will also assist in monitoring for longer term side effects, as yet unknown since the vaccines haven't been in existence long enough to know. According to CDC, not all vaccine side effects happen immediately after vaccination.

CDC also notes that, as of December 18, it had confirmed six anaphylaxis cases, or severe allergic reaction, following the vaccination.

Appropriate medical treatment used to manage immediate allergic reactions must be immediately available in the event an acute anaphylactic reaction occurs following administration of the vaccine.

CDC's Thomas Clark, MD, MPH

The allergic reaction reports prompted CDC to recommend reinforcing measures to recognize, respond to, and report anaphylaxis. The agency also says that "Persons with anaphylaxis following COVID-19 vaccination should not receive additional doses of COVID-19 vaccine."

CDC reports that as of December 19, 272,001 doses of COVID-19 vaccine had been administered.

Effectiveness

Pfizer-BioNTech

Pfizer studies found effectiveness for two months.

Moderna

Moderna studies found effectiveness (reduced risk) of confirmed coronavirus for at least 14 days after the second dose (as of December 17).

CDC notes that "observed outcome of vaccine efficacy at two months does not directly inform vaccine efficacy for any duration longer than two months." In other words, there is no way to know whether the vaccine is effective for any period longer than the time period it has been given to patients.

CDC information on Pfizer vaccine:

https://www.cdc.gov/vaccines/acip/meetings/downloads/slides-2020-12...

FDA information on Moderna vaccine:

https://www.fda.gov/media/144638/download

https://www.fda.gov/media/144585/download

https://www.fda.gov/media/144637/download

More information from CDC:

https://www.cdc.gov/mmwr/volumes/69/wr/mm6950e2.htm?s_cid=mm6950e2_w

https://sharylattkisson.com/2020/12/cdc-more-than-5000-covid-19-vac...