There are now two COVID-19 vaccines that, at least according to preliminary reports, appear to be 94.5% and 95% effective. Both were developed in a record-breaking 11 months or so.
I am an infectious diseases specialist and professor at the University of Virginia. I care for patients with COVID-19 and am conducting the local site for a phase 3 clinical trial of Regeneron's antibody cocktail as a tool to prevent household transmission of COVID-19. I'm also conducting research on how dysregulation of the immune system during SARS-CoV-2 infection causes lung damage.
Despite the vaccines' relatively rapid development, the normal safety testing protocols are still in place.
How long does most vaccine development take?
Vaccines typically take at least a decade to develop, test and manufacture. Both the chickenpox vaccine and FluMist, which protects against several strains of the influenza virus, took 28 years to develop. It took 15 years to develop a vaccine for human papilloma virus, which can cause six kinds of cancer.
It also took 15 years to develop a vaccine for rotavirus, which commonly causes severe, watery diarrhea. It took Jonas Salk six years to develop and test the first polio vaccine, starting with the isolation of the virus.
The Pfizer-BioNTech and the Moderna COVID-19 messenger RNA vaccines, by contrast, have been developed in less than a year. That's a game-changer.
How was this vaccine developed so quickly?
The mRNA vaccines produced by Pfizer and Moderna are faster to develop as they do not require companies to produce protein or weakened pathogen for the vaccine.
Traditional vaccines typically use a weakened version of the pathogen or a protein piece of it, but because these are grown in eggs or cells, developing and manufacturing vaccines takes a long time.
By contrast, by using just the genetic material that makes the Spike glycoprotein – the protein on the surface of the coronavirus that is essential for infecting human cells – the design and manufacture of the vaccine is simplified.
The genetic material mRNA is easy to make in a laboratory. Manufacturing an mRNA vaccine rather than a protein vaccine can save months, if not years.
Another factor that accelerated vaccine development was the swift and efficient recruitment of patients for clinical trials.
How is safety assured when vaccine development is so fast?
Safety is the first and foremost goal for a vaccine.
In my opinion, safety is not compromised by the speed of vaccine development and emergency use authorization. The reason that vaccines may be approved so quickly is that the large clinical trials to assess vaccine efficacy and safety are happening at the same time as the large-scale manufacturing preparation, funded by the federal government's Operation Warp Speed program.
Typically, large-scale manufacturing begins only once the vaccine has been tested in clinical trials.
In the case of COVID-19, the U.S. government wanted to be ready to begin distributing the vaccine the moment the results of the phase 3 trials were known and the safety data had been analyzed.
To this end, the pharmaceutical companies launched at-risk manufacturing – which means that the manufactured vaccine doses would be thrown away if the vaccine was ineffective or unsafe – during the FDA-mandated two-month safety waiting period.
The upside is that if the vaccine is safe and effective, it can be distributed immediately, and vaccination can begin.
Are these vaccines riskier than others?
No mRNA vaccines have been approved before because it is relatively new technology.
But these mRNA vaccines appear safe and no riskier than other tried and tested ones, like the childhood measles vaccine. To date, no significant side effects have been reported in the interim phase 3 studies of the Moderna and Pfizer vaccines.
Side effects that have been reported are minor things that one would expect with any vaccine, including soreness at the site of injection and transient fatigue, muscle or joint aches.
How will EUA work?
EUA stands for emergency use authorization.
Under EUA, the FDA is requiring that a COVID-19 vaccine be at least 50% effective at preventing symptomatic illness.
It is also requiring a median of two months of follow-up after completion of the vaccination for half of the vaccine recipients (for most of the vaccines this is two doses). This two-month period is to allow detection of an adverse event from the vaccine.
This article was originally published by The Conversation. You can read it here.
Ultrasound of human baby.Image via 
IVF animated process.Image via 
A couple speaks with a fertility professional.Image via 
Love, Mom.Photo from Heidi Johnson 
A teen boy having a hard time. 
Hands hold a digital representation of the brain.Image via 
Mother and daughter work a puzzle.Image via 
Man and woman connect under the sunshine.Image via 
The obituary paints a comic, if bleak, picture. 
A Facebook post about the obituary.
Why do some folks use social media but don't engage?
Psychologist says people who never comment on social media share these 5 positive traits
For over 20 years, social media has developed into a staple in many people’s day-to-day lives. Whether it’s to keep in communication with friends and family, following the thoughts of celebrities, or watching cat videos while sipping your morning coffee, there seem to be two types of social media users: commenters and lurkers.
The term “lurker” sounds equally mysterious and insidious, with some social media users writing them off as non-participants at best or voyeurs at worst. However, mindfulness expert Lachlan Brown believes these non-commenters have some very psychologically positive and healthy traits. Let’s take a look at how each one of these traits could be beneficial and see how fruitful lurking might be even though it can drive content creators crazy.
1. Cautious about vulnerability
Consciously or not, making a post online or commenting on one puts you and your words out there. It’s a statement that everyone can see, even if it’s as simple as clicking “like.” Doing so opens yourself up to judgment, with all the good, bad, and potential misinterpretation that comes with it. Non-commenters would rather not open themselves up to that.
These silent users are connected to a concept of self-protection by simply not engaging. By just scrolling past posts or just reading/watching them without commentary, they’re preventing themselves from any downsides of sharing an opinion such as rejection, misunderstanding, or embarrassment. They also have more control on how much of themselves they’re willing to reveal to the general public, and tend to be more open face-to-face or during one-on-one/one-on-few private chats or DMs. This can be seen as a healthy boundary and prevents unnecessary exposure.
Considering many comment sections, especially involving political topics, are meant to stir negative emotional responses to increase engagement, being extra mindful about where, when, and what you comment might not be a bad idea. They might not even take the engagement bait at all. Or if they see a friend of theirs post something vulnerable, they feel more motivated to engage with them personally one-on-one rather than use social media to publicly check in on them.
2. Analytical and reflective mindset
How many times have you gone onto Reddit, YouTube, or any other site and just skimmed past comments that are just different versions of “yes, and,” “no, but,” or “yes, but”? Or the ever insightful, formerly popular comment “First!” in a thread? These silent browsers lean against adding to such noise unless they have some valid and thoughtful contribution (if they bother to comment period).
These non-posters are likely wired on reflective thinking rather than their initial intuition. Not to say that all those who comment aren’t thoughtful, but many tend to react quickly and comment based on their initial feelings rather than absorbing the information, thinking it over, researching or testing their belief, and then posting it. For "lurkers," it could by their very nature to just do all of that and not post it at all, or share their thoughts and findings privately with a friend. All in all, it’s a preference of substance over speed.
3. High sense of self-awareness
Carried over from the first two listed traits, these silent social media users incorporate their concern over their vulnerability and their reflective mindset into digital self-awareness. They know what triggers responses out of them and what causes them to engage in impulsive behavior. It could be that they have engaged with a troll in the past and felt foolish. Or that they just felt sad after a post or got into an unnecessary argument that impacted them offline. By knowing themselves and seeing what’s being discussed, they choose to weigh their words carefully or just not participate at all. It’s a form of self-preservation through restraint.
4. Prefer to observe rather than perform
Some folks treat social media as information, entertainment, or a mix of both, and commenting can feel like they’re yelling at the TV, clapping alone in a movie theater when the credits roll, or yelling “That’s not true!” to a news anchor that will never hear them. But contrary to that, social media is a place where those yells, claps, and accusations can be seen and get a response. By its design, social media is considered by experts and the media as performative, regardless of whether it is positive or negative. Taking all of the previously mentioned traits into account, one can see why they would prefer to “observe the play” rather than get up on the stage of Facebook or X.
On top of that, these non-commenters could be using social media differently than those who choose to fully engage with it. Using this type of navigation, there may be nothing for them to comment about. Some commenters are even vying for this for their mental health. There are articles about how to better curate your social media feeds and manipulate algorithms to create a better social media experience to avoid unnecessary conflict or mentally tiring debate.
If you go on a blocking spree on all of your accounts and just follow the posters that boost you, it could turn your social media into a nice part of your routine as you mainly engage with others face-to-face or privately. In terms of commenting, if your curated Instagram is just following cute dogs and all you have to offer for a comment is “cute dog,” you might just enjoy the picture and then move on with your day rather than join in the noise. These non-commenters aren’t in the show and they’re fine with it.
5. Less motivated by social validation
The last trait that Brown showcases is that social media users who browse without posting tend to be independent from external validation, at least online. Social media is built to grow through feedback loops such as awarding likes, shares, and reposts of your content along with notifications letting you know that a new person follows you or wants to connect. This can lead many people to connect their activity on social media with their sense of self worth, especially with adolescents who are still figuring out their place in the world and have still-developing brains.
Engaging in social media via likes, shares, comments, and posts rewards our brains by having them release dopamine, which makes us feel good and can easily become addictive. For whatever reason, non-commenters don’t rely on social media as a means to gauge their social capital or self worth. This doesn’t make them better than those who do. While some non-commenters could have healthier ways to boost their self worth or release dopamine into their systems, many get that validation from equally unhealthy sources offline. That said, many non-commenters’ silence could be a display of independence and self confidence.
Whether you frequently comment online or don’t, it’s good to understand why you do or don’t. Analyzing your habits can help you determine whether your online engagement is healthy, or needs to be tweaked. With that information, you can then create a healthy social media experience that works for you.