Read on Twitter
1/ At this time, we don’t yet have data showing if Pfizer-BioNTech mRNA COVID-19 #vaccine can prevent asymptomatic infection *or* transmission of the virus 
SARS-CoV-2.We only have data showing it can prevent those vaccinated from getting the clinical disease of #COVID19.
2/ In English: We know Pfizer COVID-19 vaccine offers excellent ‘direct protection’ to vaccinated folks
We don’t yet know if unvaccinated folks will get ‘indirect protection’ from vaccinated humans.
[based on publicly available data at this time - reference at end of
]
3/ What this means:Potential risk of vaccinated humans getting asymptomatic #SARSCoV2
infection is unknown at this time. Whether
infection causes symptoms or not, vaccinated humans may still pose theoretical risk acting as ‘vectors’ (human transporter) of #SARSCoV2.
4/ Currently unknown: If a vaccination program relying on Pfizer mRNA #vaccine alone can create ‘herd immunity’ to protect unvaccinated folks.
[Emergency authorizations were granted for Pfizer vaccine’s excellent *efficacy* in preventing mild/moderate COVID-19 disease.]
5/ Implication [applies to all 
]: Without Vaccine Effectiveness data showing that vaccination prevents *transmission* of #SARSCoV2
by infected humans, prevention & control measures aim to 
community transmission still needed (may be relaxed) even for vaccinated folks.
