COVID Variants vs. Coronavirus Vaccines (AstraZeneca, Pfizer, Moderna, Johnson & Johnson) + Immunity

World News

COVID Variants vs. Coronavirus Vaccines (AstraZeneca, Pfizer, Moderna, Johnson & Johnson) + Immunity

Renowned virologist Shane Crotty, PhD joins us again to address the most important COVID-19 questions: Should people who’ve been vaccinated or had COVID-19 continue to wear masks and physically distance? How will each vaccine hold up to the SARS-CoV-2 variants? What does the research say about people who’ve already had COVID-19 who get a vaccine? How long will immunity last for the vaccines or COVID-19 infection?

Shane Crotty is a Professor at the La Jolla Institute for Immunology, Center for Infectious Disease and Vaccine Research, Crotty Lab. Prof. Crotty also has an academic appointment with the University of California San Diago. See his full bio here:
Prof. Crotty on Twitter:

Interviewer: Kyle Allred, Physician Assistant, Producer and Co-Founder of

(This video was recorded on March 23, 2021)

Just to clarify at 8:40 in the video: Prof. Crotty is describing a theoretical person when he says “I myself am comfortable getting infected…” He hasn’t had COVID, and doesn’t have that opinion. He was explaining one end of the spectrum of level of concern for individuals.


0:00 Intro
0:46 Heated exchange between Dr. Fauci and Senator Rand Paul
1:00 How long does immunity last for those who’ve had COVID-19?
3:31 How antibody levels and T cells drop over time
4:03 Dr. Fauci: Difference between in vitro and real-world studies
4:36 Population-based studies about COVID 19 immunity against reinfection
6:22 Huge variability from person to person for post coronavirus immunity
8:20 Policy decision: individual vs. community goals during a pandemic
9:03 Very rare for hospitalization from COVID-19 reinfection
9:34 Avoiding COVID-19 infection and transmission potential
10:12 Should mask-wearing continue for those who’ve had COVID-19?
12:23 If I’ve had COVID-19, shouldn’t my vaccine dose go to someone else?
13:39 Vaccines are eliciting more immunity than natural infection
14:02 Is natural immunity always better than a vaccine?
20:05 If you’ve had COVID-19, when should you get vaccinated? Both doses?
22:07 How are variants “game changers” for vaccines and natural infections?
24:53 Can’t I stop wearing masks and distancing after a vaccine or having COVID?
26:14 Variants of concern: B.1.1.7 (UK) and B.1.351 (S. Africa) details and implications
30:57 South Africa Variant escaping immunity: AstraZeneca Vaccine data
32:28 Isn’t preventing COVID 19 hospitalizations and deaths the primary goal?
35:25 Will we need updated coronavirus vaccines?
36:38 Johnson and Johnson vaccine versus the variants
37:57 Preventing transmission to prevent SARS CoV 2 mutation opportunities
38:40 Coronavirus antibodies vs T Cells and other parts of the immune system
39:54 Replication and asymptomatic spread of COVID-19 vs. Pneumonia
42:53 Vaccine incentives and Senator Rand Paul’s perspective
45:35 Looking ahead, SARS-CoV-2 vs Influenza, Will we need annual vaccinations?
52:20 Current research and goals for Prof. Shane Crotty



Crotty’s Research Published in Science |

Variant Tracker |

Denmark Research in the Lancet |

UK SIREN study:

Research from Qatar |

UK Research in NEJM |


Congressional Hearing 3/8/21: exchange with Dr. Fauci and Rand Paul: (PBS News Hour) and (CNBC)


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Video Produced by Kyle Allred


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