How will a Covid-19 vaccine travel?

In the last decade, the world has seen a steady increase in travel and tourism that undoubtedly influenced the trajectory of the Covid-19 pandemic. People flew in and out of China six times more daily in 2018 than in 2002, the year SARS, the first coronavirus to become lethal to humans, first appeared. Just as travel, and global mobility in general, has changed the speed and distance that infectious diseases can spread, Covid-19 will undoubtedly affect the way we travel.

But what about the Covid-19 vaccine? Will the Pfizer vaccine about to be approved in the United States make travel safe again? At the moment, what we know about the Pfizer vaccine in particular is that it most likely protects against mild diseases and, although this data is weaker, serious. What we don’t know, what potential travelers need to consider, is whether the vaccine prevents or at least reduces infection and transmission. We also don’t know how long vaccine-mediated protection lasts. It can be months, a year or more.

Until enough time passes, we will not be able to measure any of the variables. How we behave in the meantime, then, is the question. Even if preventive measures and travel restrictions are maintained, once a safe and effective vaccine is available for mass use, we can expect public attitudes and behaviors to change accordingly. Once vaccinated, people who have sheltered at home since spring will be tempted to flee the cooperative and catch the next flight to their dream destination, be it Grandma’s house, Honolulu, or Honduras.

You can’t blame them either. If public health interventions had been applied with the right strategy and rigor early in the pandemic, many more of us could be back home for the holidays. However, as long as we do not know whether vaccinated people can contract and spread diseases, we will have to act with as much caution as ever. That means keeping wearing masks, washing our hands, and yes, social distancing. Vaccinated or not, we could very well continue to be disease vectors. Until we know for sure that this is not the case, discarding the habits we have formed to protect ourselves and those around us will not end well.

While some policies are necessarily here to stay, others will have to be redesigned to accommodate the realities of mass vaccination. One is the travel policy that China debuted last month that requires, in addition to a negative PCR test result for Covid-19, a negative IgM antibody test result. The PCR test measures the amount of viral RNA in the nasopharynx, while the IgM test essentially detects whether or not the body has produced an initial antibody response against Covid-19. Those who receive a vaccine can test positive for Covid-19 specific antibodies despite being protected from disease. Unless the rule changes, it will be difficult for those vaccinated to travel to China.

There is another potential complication, although much less likely. Some of the RNA used to develop the Pfizer and Moderna vaccines, both unprecedented and created with the same technology, could have longer half-lives than expected, making it detectable by the average PCR test. Tried and true methods that take advantage of other parts or forms of the virus, such as the proteins that are used to develop subunit vaccines, would be easier to work around, but at least in the United States there is no horizon for implementation yet.

All in all, we must face the fact that a Covid-19 vaccine, no matter how successful, will not be enough to pave the bumpy road ahead, let alone when it comes to travel. Rather than planning and preparing for a post-pandemic world, we should hold onto a kind of hazy limbo, knowing that if we continue to follow safety guidelines and are very careful in the future, even after getting vaccinated, we will be so far closer. to end the current crisis forever.

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