ricardo00

For Moderna and Pfizer, they are the same exact composition. It is a bit more complex than that, their are lymphocytes (T cells and B cells), macrophages and memory cells, etc that are being stimulated as well.

David Martin Loc: Cary, NC

For Pfizer and Moderna vaccines, dose 1 and dose 2 are identical. Each dose consists of a strand of viral messenger RNA surrounded by a protective lipid nanoparticle coat.

The vaccine works by programming the immune system to recognize the protein spike on the surface of the virus (rather than recognizing the whole virus), and ultimately via antigen-presenting cells and helper T cells, will cause B cells to make antibodies specifically against the spike protein, and hopefully program T killer cells to kill any cells infected with the virus.

Scruples Loc: Brooklyn, New York

As a pharmacist, I have been following this Pandemic since its inception. While the statistics are difficult to understand, the human immune system is complex and has many features some of which are redundant. To insure the best possible opportunity for the human body to establish a sufficient antibody titer, the secondary dose is necessary. There are other vaccines that require "booster" doses. In a simplified explanation, the second dose is a reminder for the immune system as to what it needs to do. Many people have chosen not to take the second dose after they have had a reaction to the first dose. Upon receipt of the first dose, I did not experience any adverse effects. I am not sure if the second dose may cause me to feel any untoward reaction. I will know in a few days. As further post marketing surveillance is performed, more knowledge will be gained.

Scruples Loc: Brooklyn, New York

This is correct but it is very difficult to explain to many people even medical personnel. I must commend you for explaining the vaccine in a manner I did my best to avoid everyone from skipping past.

Dossile

I have read many of the reports, and also critiques of the reports, provided by both Pfizer and Moderna. The second dose is important in establishing near universal absolute immunity. The first dose provides immunity to a significant part of the population but still allows for many to become infected. No person infected after receiving the first dose of vaccine has ended up in the hospital though. So even just getting one dose is important in preventing severe infections. I’m always grateful when people say they are getting vaccinated. A COVID infection is very dangerous, a COVID vaccine is not without risks, but is not terribly dangerous.

The immune system is extremely complex and very incompletely understood. We will learn a lot from COVID. But in regards to basics there are two main forms of infectious immunity, cellular and humoral. One is created by cells attacking infectious organisms (cellular). The other type of immunity is created by cells creating compound proteins (immunoglobulins like IgG and IgM) that latch onto the organisms and allow the body to destroy the organisms (humoral). When people talk about serum levels, they are talking about levels of immunoglobulins. The cellular immunity is every bit as important as humoral immunity and is more difficult to measure with tests. Both forms of immunity are created with the COVID vaccines and the second dose seems important for establishing both forms of immunologic memory, but possibly more so for cellular immunity. I expect that we will may get a third dose, a booster, in 8-10 months, but that is personal conjecture at this stage.

nervous2 Loc: Provo, Utah

Had first Moderna injection 3 weeks ago and scheduled for second next Friday. Very grateful to be able to get both. I understand that reaction to second can be significantly greater than reaction to first, which in my case was not bad.

sodapop Loc: Bel Air, MD

The nurse who gave me the first shot told me that the vaccine is exactly the same. You get a total of 1 cc, half the first shot half the second She stated that that provides optimal performance.

jackm1943 Loc: Omaha, Nebraska

I'm not certain I can follow the numbers but, virtually always, you will have better immunity to any vaccine following a booster, even if the first dose provides some protection.

OnDSnap Loc: NE New Jersey

Perhaps do to the persistence of the virus, where one shot won't win the war on training the immune system to recognize the virus, build the antibodies and battle it the next time it rears it's nasty head. Just a guess. BTW, It will never be banished so long as there are those who don't wear masks, socially distance from others and refuse the vaccine.

David Martin Loc: Cary, NC

Even those measures may not be enough to "banish" the virus. Because viruses may not simply go away.

For example, the 1918 influenza virus ("Spanish flu") never went away. Gene sequencing has shown that the same strain of flu that caused the 1918 pandemic is the ancestor of every subsequent seasonal flu:

“You can still find the genetic traces of the 1918 virus in the seasonal flus that circulate today,” says Taubenberger. “Every single human infection with influenza A in the past 102 years is derived from that one introduction of the 1918 flu.”
https://www.history.com/news/1918-flu-pandemic-never-ended

And although most flu seasons are not pandemics, the 1957, 1968 and 2009 seasons were particularly lethal. We should be prepared for a similar scenario with SARS-Cov-2 (Covid-19).

patman1 Loc: Pataskala, Ohio

Just a quick question, does anyone wonder why on the box or bottle, it's not called a vaccine?
I recently saw a video of Bill Gates in conference showing the CIA the vaccine he has developed to alter ones DNA, very convincing I think everyone should view it and make their own decisions, me I decided not to take the vaccine, I'm in Gods hands! Stay safe, stay well, be careful

patman1 Loc: Pataskala, Ohio

If anyone is interested in seeing the video I can forward the link in messenger! Advise

IDguy Loc: Idaho

Good. Others more deserving will get it. And you are might help the gene pool.

When I see these views I remind myself half the population are below average intelligence. And some way below.

I just hope you do not kill too many others by spreading it.

IDguy Loc: Idaho

They obviously are not “exactly” the same. If they were the storage conditions and interval between shots would be the same.

It might be fair to say the way they work is similar. And even similar enough that the CDC experts advise you can mix and match and get a similar result. That is, the second shot can be the other vaccine from the first. There is no testing to support that idea but it must be a logical guess by those who know a lot more about this than I do.

IDguy Loc: Idaho

Oh, and as I understand it the doses are very different too.