And even if people could pick and choose now, experts say, that would likely hinder the goal of mass vaccination - which is to protect as many lives as quickly as possible.
The FDA's recently released review of Johnson & Johnson's vaccine, which is expected to be authorized as early as this weekend, found that it was more than 80 percent effective at preventing severe illness in a large worldwide clinical trial.
Bahrain became the first nation to authorize Johnson & Johnson's new single-dose coronavirus vaccine for emergency use on Thursday, the government announced, just a day after USA regulators concluded the shot offers strong protection against severe COVID-19. It is expected that the panel will grant the company's application for emergency use.
This makes it slightly less protective than the Pfizer and Moderna's two-shot regimens, which both have an efficacy of around 95 percent against all forms of Covid-19 from the classic coronavirus strain.
State health officials urged people not to get too caught up in differences between efficacy rates between the different vaccines, because they are all effective in preventing COVID-19 deaths and hospitalizations.
Health authorities in Germany and other countries have raised concerns that AstraZeneca didn't test the vaccine in enough older people to prove it works for them, and indicated they would not recommend it for people over 65.
The committee was charged with voting on the following question: "Based on the totality of scientific evidence available, do the benefits of the Janssen COVID-19 Vaccine outweigh its risk for use in individuals 18 years of age and older?" "So these are the vaccines that we need if we want to be having all the pharmacies vaccinating, all the family doctors' offices vaccinating, it's much, much easier to work with these". The side effects usually lasted a couple of days after the shot.
Despite declining cases, hospitalisations and deaths, government scientists warned that circulating variants could slow progress against the pandemic.
Pfizer, Moderna or maybe J&J? Right now, the best vaccine for you is the one you can get.
Biden administration officials have said the USA expects J&J to release 3 million to 4 million shots next week, assuming it's authorized for use. It will also receive up to 1.9 million doses through the global vaccine-sharing initiative known as COVAX by the end of June.
Canada does have a deal in place to buy 20 million doses of the AstraZeneca vaccine but the government is now working overtime trying to renegotiate delivery since the original contract doesn't allow those doses to start shipping until after March. "When it's your turn, you should take whichever one is offered".
The J&J vaccine is also easier to handle, lasting three months in the refrigerator compared to the Pfizer and Moderna options, which must be frozen.
Other parts of the world already are facing which-is-best challenges.
Italy's government recently made a decision to reserve Pfizer and Moderna shots for the elderly and designate the AstraZeneca vaccine for younger, at-risk workers, sparking protest from the country's main teachers' union.
"We may be done with the virus, but clearly the virus is not done with us", Centers for Disease Control and Prevention director Dr. Rochelle Walensky, said, speaking at the White House on Friday. AstraZeneca's vaccine was deemed to be about 70 per cent effective in testing.
Trudeau spoke on Friday hours after Health Canada announced it had approved a COVID-19 vaccine from AstraZeneca.