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Jessica McDonald

@jjmcdona.bsky.social

Science Editor, FactCheck.org Previously with WHYYNews, Science Friday, AAAS Mass Media Fellow at KUNC. Yale Immunobiology Ph.D.

101 Followers  |  27 Following  |  18 Posts  |  Joined: 13.11.2024  |  1.7032

Latest posts by jjmcdona.bsky.social on Bluesky

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No FR announcement, inside 15-days, and now meeting date updated to โ€œTBDโ€ on ACIP website.

08.10.2025 12:49 โ€” ๐Ÿ‘ 6    ๐Ÿ” 1    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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Vaccine Advisory Committee Members Mislead About COVID-19 Vaccination During Pregnancy - FactCheck.org A substantial body of evidence supports the safety of the COVID-19 vaccines during pregnancy, contrary to the suggestions of some members of the Centers for Disease Control and Preventionโ€™s vaccine ad...

One of my wonkiest yet. A deep dive on the single data point from Pfizer's COVID-19 maternal vaccine trial that's being used to argue against vaccination. www.factcheck.org/2025/10/vacc...

03.10.2025 18:21 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Trump Misleads on Climate Change and Renewables at U.N. - FactCheck.org In an hourlong address before the U.N. General Assembly on Sept. 23, President Donald Trump lashed out at those promoting "the green energy agenda." Along the way, he made numerous false and misleadin...

Trump is back to calling global warming a "hoax." We break down some of his claims in his U.N. speech. www.factcheck.org/2025/09/trum...

26.09.2025 15:23 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Trump Administration's Problematic Claims on Tylenol and Autism - FactCheck.org In a Sept. 22 press conference that he hadย billedย as โ€œone of the biggest [medical] announcements โ€ฆ in the history of our country,โ€ President Donald Trumpย toutedย an unproven link between autism and the...

For those with questions about Tylenol, in light of the White House press conference, please see our story: www.factcheck.org/2025/09/trum...

25.09.2025 16:40 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Repeated Falsehoods at Autism Press Conference - FactCheck.org An hourlong press conference about autism was filled with false and misleading claims about the condition and vaccines from President Donald Trump and Health and Human Services Secretary Robert F. Ken...

So many claims in the autism presser, many of them familiar to us.

Check them out here, including Trump's more novel claim about giving the vaccines in MMR separately. That goes back to Andrew Wakefield (yikes!) & it's not even possible to do!

www.factcheck.org/2025/09/repe...

24.09.2025 16:11 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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The Facts Behind Claims on Autism, Tylenol and Folate - FactCheck.org News reports have indicatedย Health and Human Services Secretary Robert F. Kennedy Jr. may point to Tylenol and folate deficiency in his promised announcement on the causesย of autism. But neither Tylen...

Some good background reading before today's White House announcement, by @kateyandell.bsky.social. www.factcheck.org/2025/09/the-...

22.09.2025 18:20 โ€” ๐Ÿ‘ 0    ๐Ÿ” 1    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Dear ACIP,
Informed consent is a state issue.

The Vaccine Information Statement is a federal document that needs to be give to people before vaccinating. CDC can change it - after a long process, and in consultation with the Advisory Commission of Childhood Vaccines.

1/2

19.09.2025 18:56 โ€” ๐Ÿ‘ 56    ๐Ÿ” 17    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 1
Screenshot of the header of Secretary Kennedyโ€™s justification for repealing the recommendation for COVID vaccination to children and pregnant individuals (linked in the post).

Screenshot of the header of Secretary Kennedyโ€™s justification for repealing the recommendation for COVID vaccination to children and pregnant individuals (linked in the post).

Today, #ACIP will be voting on #CovidVaccination. I will be examining a PhD viva at the time and won't be able to follow live.

So, to anticipate some of the claims that may be made on COVID vaccination in #pregnancy... ๐Ÿงต

www.cidrap.umn.edu/sites/defaul...

19.09.2025 12:58 โ€” ๐Ÿ‘ 51    ๐Ÿ” 26    ๐Ÿ’ฌ 3    ๐Ÿ“Œ 2
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Cleveland Clinic Study Did Not Show Vaccines Increase COVID-19 Risk - FactCheck.org Numerous studies have found that additional COVID-19 shots are generally associated with extra protection against the coronavirus. Many people on social media, however, have shared a preliminary findi...

The perennial favorite, Cleveland Clinic study
www.factcheck.org/2023/06/scic...

19.09.2025 16:49 โ€” ๐Ÿ‘ 0    ๐Ÿ” 1    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Viral Posts Misuse Rat Study to Make Unfounded Claims About COVID-19 Vaccines and Autism - FactCheck.org COVID-19 vaccination during pregnancy benefits both mother and baby. Side effects are generally mild, and studies donโ€™t show negative effects on the baby. A criticized study that gave COVID-19 vaccine...

That rat "autism" study Griffin mentioned:
www.factcheck.org/2024/01/scic...

19.09.2025 16:49 โ€” ๐Ÿ‘ 0    ๐Ÿ” 2    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
https://www.factcheck.org/2022/10/scicheck-no-indication-breast-milk-after-vaccination-unsafe-despite-posts-about-new-study/

Also mentioned, by various members:
COVID-19 vaccine and breast milk
www.factcheck.org/2022/10/scic...

19.09.2025 16:49 โ€” ๐Ÿ‘ 1    ๐Ÿ” 1    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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COVID-19 Vaccines Have Not Been Shown to Alter DNA, Cause Cancer - FactCheck.org Small amounts of DNAย from the manufacturing process may remain in the mRNA COVID-19 vaccines. Purification andย quality control steps ensure any leftover DNA is present within regulatory limits. There ...

#ACIP meeting today is veritable rehash of many vaccine misinfo claims.

Focused a lot on dubious claims of DNA contamination in the COVID-19 vaccines.

Please see here: www.factcheck.org/2023/10/scic...

19.09.2025 16:49 โ€” ๐Ÿ‘ 5    ๐Ÿ” 3    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

I think it was Pagano, not Malone, who asked this, but I would have to check again to be sure. Video is small and hard to see.

18.09.2025 21:05 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
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Dropping hepatitis B shots for newborns would ignore history and endanger children, scientists warn People who study, treat, or have hepatitis B say ending routine vaccination at birth - as some vaccine critics want - could lead to a resurgence of the virus.

If you read 1 thing today, please make it this: my so-talented colleague @ericboodman.bsky.social explains why babies in the US are vaccinated at birth against hep B โ€” and what the human costs of changing that policy would be. www.statnews.com/2025/09/11/n...

11.09.2025 12:28 โ€” ๐Ÿ‘ 271    ๐Ÿ” 125    ๐Ÿ’ฌ 5    ๐Ÿ“Œ 4
DOE CWG STATEMENT (second paragraph of section 2.1.1, page 3): โ€œPiao et al. (2020) noted
that greening was even observable in the Arctic.โ€
COMMENT: This statement implies that the Arctic greening signal was caused by elevated CO2
,
however that is not the scientific consensus. Piao et al. (2020) attribute the greening trend in the
Arctic predominantly to growing season length driven by warmer temperatures (see also Y.
Zhang et al., 2022). Piao et al. (2020) also note that this positive impact of increasing
temperatures appears to have weakened over the past four decades, โ€œsuggesting a possible
saturation of future greening in response to warmer temperatureโ€ (see also comment on
greenness trends related to Section 2.1.1, first sentence of Page 4). It is also important to put
Arctic greening more broadly into the context of the carbon cycle and other impacts. While
above-ground plants may have displayed more leaf area over the past decades, rising
temperatures also thaw permafrost and drive accelerated decomposition in highly carbon rich
soils (Turetsky et al., 2020), a process which is expected to accelerate as climate continues to
warm (Miner et al., 2022). Thus even with Arctic greening, high latitude terrestrial systems may
become net carbon sources to the atmosphere, causing an amplifying feedback (Braghiere et
al., 2023). Other risks to the Arctic linked to higher CO2

levels and rising temperatures are not
mentioned in this report (Virkkala et al., 2025). The Arctic is warming at a rate of 2 to 3 times the
global average, leading to thawing of permanently frozen soils (permafrost), with downstream
impacts including loss of structural support for buildings and subsidence, threatening
communities, roads, runways, and other assets across Alaska (Manos et al., 2025; University of
Alaska Fairbanks Institute of Northern Engineering US Army Corps of Engineers Alaska District
& Laboratory, 2019).

DOE CWG STATEMENT (second paragraph of section 2.1.1, page 3): โ€œPiao et al. (2020) noted that greening was even observable in the Arctic.โ€ COMMENT: This statement implies that the Arctic greening signal was caused by elevated CO2 , however that is not the scientific consensus. Piao et al. (2020) attribute the greening trend in the Arctic predominantly to growing season length driven by warmer temperatures (see also Y. Zhang et al., 2022). Piao et al. (2020) also note that this positive impact of increasing temperatures appears to have weakened over the past four decades, โ€œsuggesting a possible saturation of future greening in response to warmer temperatureโ€ (see also comment on greenness trends related to Section 2.1.1, first sentence of Page 4). It is also important to put Arctic greening more broadly into the context of the carbon cycle and other impacts. While above-ground plants may have displayed more leaf area over the past decades, rising temperatures also thaw permafrost and drive accelerated decomposition in highly carbon rich soils (Turetsky et al., 2020), a process which is expected to accelerate as climate continues to warm (Miner et al., 2022). Thus even with Arctic greening, high latitude terrestrial systems may become net carbon sources to the atmosphere, causing an amplifying feedback (Braghiere et al., 2023). Other risks to the Arctic linked to higher CO2 levels and rising temperatures are not mentioned in this report (Virkkala et al., 2025). The Arctic is warming at a rate of 2 to 3 times the global average, leading to thawing of permanently frozen soils (permafrost), with downstream impacts including loss of structural support for buildings and subsidence, threatening communities, roads, runways, and other assets across Alaska (Manos et al., 2025; University of Alaska Fairbanks Institute of Northern Engineering US Army Corps of Engineers Alaska District & Laboratory, 2019).

Our comment on the DOE CWG report is done. It tips the scales at 439 pages, approx. 3x longer than the DOE report.
This is related to Brandolini's law: The amount of energy needed to refute bullshit is an order of magnitude bigger than that needed to produce it.

Example: refuting one sentence.

28.08.2025 01:13 โ€” ๐Ÿ‘ 368    ๐Ÿ” 141    ๐Ÿ’ฌ 11    ๐Ÿ“Œ 25
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Behind R.F.K. Jr.โ€™s Vow to โ€˜Follow the Scienceโ€™ on Vaccines Robert F. Kennedy Jr. cited a disputed study from a close network of fellow vaccine skeptics during his confirmation hearings. His critics say it is part of a pattern that raises concerns about whose ...

This NYT story links to my story detailing the many flaws in a study RFK Jr. cited during Senate testimony to argue that there is reliable evidence that vaccines cause autism (there isn't).
nytimes.com/2025/02/12/u...
Final vote on RFK Jr. begins in about 20 minutes.

13.02.2025 15:08 โ€” ๐Ÿ‘ 1    ๐Ÿ” 1    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Those drugs? Chloroquine and ivermectin. Which were either already disproven or unproven at the time (now both are disproven). (4/4)

07.02.2025 16:28 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

People should also really take a look at this petition & how unscientific it is. It claims that no vaccine should be authorized in part because there are already effective drugs for COVID-19. (3/4)

07.02.2025 16:28 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

RFK Jr.'s standard response when asked about his 2021 petition to revoke EUAs for all COVID vaccines is to claim that it was after CDC recommended the vaccines to 6yo kids.
Nope. Literally not possible! Petition was filed in May, CDC rec in Nov. Just one of many issues. (2/4)

07.02.2025 16:28 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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FactChecking RFK Jr.โ€™s Other Health Claims During HHS Confirmation Hearings - FactCheck.org Here, we explain the facts behind several more of Robert F. Kennedy Jr.โ€™s claims during his two Senate hearings as nominee for Health and Human Services secretary.

Let me highlight one claim here that hasn't received a lot of media attention, even though it is a blatant falsehood. (1/4)
www.factcheck.org/2025/02/fact...

07.02.2025 16:28 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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RFK Jr. Cites Flawed Paper Claiming Link Between Vaccines and Autism in HHS Confirmation Hearing - FactCheck.org In his second day of confirmation hearings, Robert F. Kennedy Jr., President Donald Trumpโ€™s pick to lead the Department of Health and Human Services, refused to say that vaccines do not cause autism -...

I was interviewed and extensively cited in this factcheck.org article discussing the methodological flaws in the Mawson paper cited by RFK, Jr. in his confirmation hearings yesterday, and mentions other much more rigorous studies finding no vax/autism association.

www.factcheck.org/2025/01/rfk-...

31.01.2025 18:01 โ€” ๐Ÿ‘ 584    ๐Ÿ” 92    ๐Ÿ’ฌ 18    ๐Ÿ“Œ 8

Really nice FAQ!

22.11.2024 19:35 โ€” ๐Ÿ‘ 13    ๐Ÿ” 5    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
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As Trump Taps RFK Jr. for Health Secretary, a Look Back at Kennedy's Claims - FactCheck.org In one of his most controversial Cabinet picks, President-elect Donald Trump said he would nominate Robert F. Kennedy Jr. to lead the Department of Health and Human Services. Here, we summarize our pa...

Make no mistake: Despite what he says (not "anti-vaccine," "an evidence-based person"), RFK Jr.'s track record on multiple health issues says otherwise.

A non-exhaustive summary of our previous fact checks of Trump's pick to head HHS.
bit.ly/4icMrtw

22.11.2024 18:40 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

Just joined! Hoping to find some semblance of the old "science Twitter" here.

13.11.2024 16:51 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0

@jjmcdona is following 20 prominent accounts