How Will Summer Really Impact Coronavirus?

March 20, 2020

Whether it’s the President of the United States or one of your friends, people all over the country are claiming summer will help get rid of the Coronavirus. But solving our COVID-19 crisis won't be as easy as waiting for warm weather to set in.


MALE_1: You've heard about it all over the place.

MALE_1: This idea that summer is somehow

MALE_1: going to kill off the coronavirus.

MALE_1: Whether it's from friends, family,

MALE_1: or even the President of the United States.

Donald Trump: They're working hard. Looks like by April, you know,

Donald Trump: in theory when it gets a little warmer,

Donald Trump: it miraculously goes away. I hope that's true.

MALE_1: But could it really be so easy to defeat COVID-19?


Louiza Petre: If we extrapolate from what

Louiza Petre: we know from the other viruses,

Louiza Petre: historically, yes,

Louiza Petre: most outbreaks do slow down in the summertime.

MALE_1: That's Louiza Petre from

MALE_1: Mount Sinai Hospital in New York.

Louiza Petre: We do have an outbreak right now in

Louiza Petre: Iran and we have cases in Singapore and Australia.

Louiza Petre: So that kind of would go against this assumption.

MALE_1: This makes one thing clear right off the bat.

MALE_1: Warm weather might slow down the spread of COVID-19,

MALE_1: but it won't stop the disease.

MALE_1: COVID-19 transmission occurs when

MALE_1: small viral droplets spread directly between people,

MALE_1: like if someone coughs and you inhale it,

MALE_1: or if those droplets got on surface that

MALE_1: you touch before touching your face.

MALE_1: This is very similar to common colds which

MALE_1: some coronaviruses cause, and the flu.

MALE_1: From what we know about these more common viruses,

MALE_1: they tend to have a harder time spreading in warmer,

MALE_1: more humid weather, like we usually see in summer.

MALE_1: To understand why, let's start with

MALE_1: those droplets that spread the virus.

MALE_1: In general, when it's more

MALE_1: humid and someone coughs or sneezes,

MALE_1: droplets like the coronaviruses tend

MALE_1: to absorb moisture from the air.

MALE_1: This weighs down the droplets more quickly,

MALE_1: forcing them to the ground sooner.

MALE_1: All of this means that those droplets tend to

MALE_1: travel less far from the infected person

MALE_1: and that they have a lower likelihood of staying

MALE_1: suspended in the air for any length of time.

MALE_1: And of course, that means they're less likely to find

MALE_1: their way into someone else's nose or mouth.

MALE_1: But when those droplets land on the ground

MALE_1: or various surfaces that others might touch,

MALE_1: they can remain contagious.

MALE_1: Early studies looking at

MALE_1: the coronavirus in perfect lab settings,

MALE_1: suggest that it can survive for

MALE_1: quite a while depending on the surface.

Louiza Petre: We've learned that the virus can survive

Louiza Petre: on paper and cardboard up to 24 hours,

Louiza Petre: and on smooth surfaces like marble counters,

Louiza Petre: metal, or plastic, it can survive up to three days.

Louiza Petre: But those are laboratory conditions,

Louiza Petre: in real life, it's probably much lower than that.

MALE_1: Warmer weather might make it just a little

MALE_1: bit harder for them to survive on surfaces.

Louiza Petre: The sweet spot for coronavirus right now,

Louiza Petre: it's established around 48, 50 Fahrenheit,

Louiza Petre: and what happens at higher humidity and temperature,

Louiza Petre: the viral particle becomes unstable,

Louiza Petre: and breaks down, and it's less contagious.

MALE_1: It's important to note here that

MALE_1: this number does not come

MALE_1: from looking at the virus under

MALE_1: a microscope, but instead,

MALE_1: from researchers at a Chinese university

MALE_1: analyzing statistically at what

MALE_1: average temperature COVID-19 spread most during

MALE_1: the early weeks of the outbreak in

MALE_1: January and February, 2020.

MALE_1: So the study is not saying that the virus just

MALE_1: spontaneously combusts above 50 degrees Fahrenheit.

MALE_1: In fact, we know it continues to spread.

MALE_1: These researchers are just asserting

MALE_1: that it spreads less effectively.

MALE_1: In a study funded by the National Institutes of Health,

MALE_1: the University of Maryland took

MALE_1: a closer look at the COVID-19 pandemic,

MALE_1: to try and get a better idea of whether

MALE_1: this reasoning played out on a global scale.

MALE_1: According to the study, COVID-19 has established

MALE_1: significant community spread in cities

MALE_1: with average temperatures between

MALE_1: about 40 and 50 degrees Fahrenheit and low humidity.

MALE_1: Those cities experience similar weather patterns

MALE_1: and are roughly distributed along the same latitude.

MALE_1: And at the same time,

MALE_1: they observed a lack of

MALE_1: significant community spread in other cities

MALE_1: with similar proximity and

MALE_1: travel to areas with outbreaks.

MALE_2: [MUSIC] One huge caveat on both of

MALE_2: these studies is that they are preliminary,

MALE_2: only looking at the viruses spread through February 2020.

MALE_2: They also need to be peer reviewed and

MALE_2: scrutinized by the wider scientific community.

MALE_2: But regardless of how the virus responds to temperature,

MALE_2: our summer lifestyles may

MALE_2: play a more significant role than

MALE_2: we realize in why

MALE_2: viruses seem to recede during the summer.

FEMALE_1: Also, there are other factors that play a role here.

FEMALE_1: One is people's behaviors.

FEMALE_1: They stay more outdoors,

FEMALE_1: they cluster less in small or poor ventilated areas.

FEMALE_1: Also in the winter months,

FEMALE_1: people do have a little lower immunity.

FEMALE_1: We have less vitamin D, less vitamin C,

FEMALE_1: and definitely those are related to

FEMALE_1: robust immunity and how we fight viruses.

MALE_2: Another perk of people spending more time outside is

MALE_2: that even if they cough and spread droplets,

MALE_2: the virus might not linger for as long on every surface.

MALE_2: If those droplets happen to land in sunlight, the U.V.

MALE_2: rays from the sun can actually make the virus inactive.

MALE_2: Because of these two factors,

MALE_2: experts suggest that the summer may help fight COVID-19,

MALE_2: but we simply cannot wait

MALE_2: until summer to address this pandemic.

FEMALE_1: We don't have time to wait until summer.

FEMALE_1: We're in the middle of an exponential outbreak

FEMALE_1: and waiting until summer would be too late.

FEMALE_1: We'll have too many cases and

FEMALE_1: too many casualties by then.

MALE_2: The Coronavirus is also so new that we really

MALE_2: just don't know exactly

MALE_2: how it will behave in warmer weather.

MALE_2: We can make predictions based on preliminary studies like

MALE_2: the one above or other viruses that we know more about,

MALE_2: but the Coronavirus could still surprise us.

MALE_2: Officials from both the Centers for Disease Control and

MALE_2: the World Health Organization have made this clear.

Dr.Maria van Kerkhove: We've only known about this virus for eight weeks.

Dr.Maria van Kerkhove: We have no reason to believe that this virus would

Dr.Maria van Kerkhove: behave differently in different temperatures,

Dr.Maria van Kerkhove: which is why we want aggressive action in

Dr.Maria van Kerkhove: all countries to make sure that

Dr.Maria van Kerkhove: we prevent onward transmission.

Dr.Maria van Kerkhove: But to look at seasonality,

Dr.Maria van Kerkhove: you need to look at patterns over

Dr.Maria van Kerkhove: time and we do need some of that time.

MALE_2: Plus just assuming this virus

MALE_2: will be seasonal can prove problematic.

MALE_2: SARS, one of the closest related viruses

MALE_2: to our current Coronavirus

MALE_2: did not demonstrate a seasonal pattern, neither has MARS.

MALE_2: Also, a new virus introduced to a population

MALE_2: spreads differently than ones that have

MALE_2: been in the population for a while.

MALE_2: This is because many people have already

MALE_2: become immune to those older viruses,

MALE_2: thus depleting the number of

MALE_2: individuals that those viruses can infect.

MALE_2: This helps explain why those older viruses

MALE_2: are seasonal because that's when

MALE_2: conditions are most advantageous and

MALE_2: they get access to more non immune individuals.

MALE_2: A new virus, on the other hand,

MALE_2: doesn't face this immunity hurdle and can therefore

MALE_2: spread through the population

MALE_2: without the seasonal limitation.

MALE_2: Then there's the fact that even

MALE_2: with the viruses we know are seasonal,

MALE_2: they don't go away forever in the summer.

MALE_2: They just recede a bit into the background,

MALE_2: still transmitting between at least some people in

MALE_2: the summer months and then they come

MALE_2: back in the winter. Think about it.

MALE_2: It's still possible to get a

MALE_2: cold or the flu in the summer,

MALE_2: it just tends to happen less frequently.

MALE_2: Also, it's not summer

MALE_2: all at once everywhere in the world.

MALE_2: Just as one summer ramps up in the northern hemisphere,

MALE_2: another winds down in the southern hemisphere.

MALE_2: That allows the virus to thrive in different places,

MALE_2: which would make it hard to stamp out what is now

MALE_2: a global pandemic by just relying on the weather.

MALE_2: So what's the takeaway?

MALE_2: Unfortunately, even in the best of

MALE_2: circumstances where this Coronavirus proves seasonal,

MALE_2: it can't do enough to get rid of COVID-19 for us.

MALE_2: It is said, "Combating the Coronavirus

MALE_2: relies on people around the world to

MALE_2: engage in techniques like

MALE_2: social distancing to help slow this pandemic down."

MALE_2: Then we can all hope that those efforts get

MALE_2: a little helpful boost from

MALE_2: the weather during the summer.

MALE_3: Of course, first and foremost,

MALE_3: make sure you follow the latest guidelines from

MALE_3: the CDC on hand sanitizer,

MALE_3: hand-washing and prevention of COVID-19.