Thread by @awong37

The benefits of vaccinating ALL children b/w ages 5-11 with Pfizer #COVID19 vaccine OUTWEIGHS known or potential risks.

A long-ish 🧵 on data & risk/benefits thus far.

As an ID physician, I'll vaccinate my 5 year-old w/ confidence, and recommend to others to do the same.

(1/n)

#COVID19 is a serious infection for all kids.

Although kids who acquire COVID are at much lower risk of death than adults, other complications can occur after recovery from acute infection, including Multisystem Inflammatory Syndrome (MIS-C), and Long #COVID.

(2/n)

Much higher rates of infection, hospitalizations, and deaths have been reported in children in last several months in the USA & Canada as a result of widespread transmission of the more contagious Delta variant.

(3/n)

Pfizer/BioNTech are conducting an ongoing clinical trial in children <12, and have requested approval for a 2-shot 10 µg of BNT162b2 for children b/w ages 5 and <12 given 3 weeks apart.

The 10 µg dose is one-third the 30 µg dose approved for those over 12.

(4/n)

2 cohorts of clinical trial participants b/w ages 5 and <12 exist.

An 'original' cohort of 2268 participants (1518 vaccine, 750 placebo), and a further 'safety expansion' cohort of 2379 participants (1591 vaccine, 788 placebo).

In total, there are 3109 vaccinated kids.

(5/n)

Vaccine effectiveness amongst the originally enrolled 2268 participants was 90.7% vs lab-confirmed COVID-19 infection.

Note: earliest COVID-19 case reported was in July 2021, majority in August / September 2021. Thus, vaccine IS protective vs Delta variant.

(6/n)

Neutralizing antibody titres in children b/w 5 and <12 were non-inferior to titres seen in young adults b/w 16-25 given 2 doses of 30 µg BNT162b2.

Additional supplemental analysis showed that neutralizing titres vs Delta variant elicited 1 month after dose 2 were robust.

(7/n)

With regards to safety and tolerability, NO cases of either pericarditis or myocarditis were observed ~3 months after dose 2 in the initially recruited cohort, or ~2.5 weeks after dose 2 in the later 'safety' cohort.

Ongoing follow-up will be needed, obviously.

(8/n)

Very few serious adverse events (SAEs) were noted in study participants, and NONE were deemed related to vaccine.

Additionally, NO adverse events were noted that led to withdrawal of a participant from the study in 3109 who received the vaccine.

(9/n)

The overall number of participants who received vaccine in the clinical trial program is too small to detect the real risk of heart inflammation associated with vaccine in this age group. Long-term follow-up is planned and will be required to best understand safety

(10/n)

Surveillance data from Israel suggests that rare events of post-vaccine myocarditis peaks in males b/w 16-19, and decreases in adolescents b/w 12-15.

Also, dosing is 1/3rd of dose given to older recipients.

Hence, can infer myocarditis rates VERY low b/w 5 and <12.

(11/n)

Assume 90% vaccine efficacy & myocarditis rates in ages 5-11 identical to ages 12-15 (likely an over-estimate). For every million vaccinated kids b/w 5-11 every 120 days in US:

- ~33,600 cases prevented
- 170 hospitalizations prevented
- ~21 heart inflammation events

(12/n)

In summary, overall benefit of reducing #COVID19 infections, hospitalizations, & deaths in kids b/w ages 5 and <12 AS WELL AS the prevention / reduction in long-term complications such as MIS-C / long COVID OUTWEIGHS potential risks (i.e. heart inflammation) of vaccine.

(13/n)

It is acknowledged that long-term safety data is unavailable and MUST be collected diligently.

Health Canada review is pending. Nearly ALL of this content was taking from the FDA technical briefing released last Friday:

fda.gov/media/153409/d…

(14/n)

We expect Health Canada conclusions to be similar to that of the FDA, meaning approval is forthcoming in Canada, followed by NACI review, and then "off we go".

Likely seeing jabs in arms by early/mid November across Canada. Earlier in the US, realistically. Yay!

(15/n)