* French PM says now not the moment to loosen the reins
* Financial markets drop back from surge on vaccine announcement
* WHO head warns 'We may be tired of COVID, it is not tired of us'
* Grim UK data underlines economic pain
By Sudip Kar-Gupta and Thomas Seythal
PARIS/BERLIN, Nov 12 (Reuters) - European officials warned against COVID-19 complacency on Thursday and said measures to control a surge in infections as winter approaches must remain in force despite hopes that new vaccines can bring the pandemic under control.
This week's announcement by Pfizer Inc of a potentially effective vaccine spurred optimism that an end to months of crisis could be in sight, sending financial markets soaring and fuelling public longing for a nearly normal Christmas.
But France and the World Health Organization urged people to continue complying with lockdowns as it became clear that the new vaccines would not come soon enough for many COVID-19 sufferers and shrinking economies.
"This is definitely not the moment to loosen up," French Prime Minister Jean Castex told newspaper Le Monde in an article published hours before he was due to deliver a keynote speech.
While Pfizer and German partner BioNTech aim to produce 50 million doses this year if the vaccine is approved in time, it will not become more widely available until 2021, leaving strained health systems to manage until then.
In Italy, which reported 623 deaths on Wednesday and passed the 1 million case milestone, and in Germany, which has also seen infections climb back to levels seen earlier in the crisis, officials said any return to normal would take time.
"We really must grit our teeth for a couple more months," said Lothar Wieler, head of Germany's Robert Koch Institute for infectious diseases. "Unfortunately it will take a while until everyone who wants to can get vaccinated."
The dire situation facing Italy, the country at the centre of the first wave of the pandemic, was underlined by a video on social media showing a corpse sprawled in a hospital lavatory, after the patient apparently died while waiting for a test.
After achieving a degree of control over the pandemic following the blanket lockdowns earlier in the year, governments across the region have scrambled to impose new restrictions to try to curb the alarming rise in case numbers in recent weeks.
But while some signs have emerged that those measures may be helping slow infection rates in some areas, authorities said more was needed.
"Infections went down fast last week, but we need to make more progress," Ernst Kuipers, head of the Dutch national hospital association LNAZ told reporters. "The measures in place are still necessary, and we keep stressing the importance of following the rules."
As euphoria following Pfizer's announcement faded, European shares slipped back from eight-month highs, with poor economic data from Britain adding to doubts about a rebound from the brutal slump following the first lockdowns.
"Dealers are starting to realise that even though a drug has a very high success rate in late-stage trials, the process of obtaining approval and getting it rolled out could take a long time," said David Madden, analyst at CMC Markets UK.
Britain, which passed 50,000 COVID-19 deaths on Wednesday, reported that its economy lost speed in September, hardening expectations that the economy will shrink again as 2020 ends.
As the crisis has ground on and jobless numbers have risen, public support for countermeasures has fractured. Several countries have seen protests and observance of rules against public gatherings or mandating mask wearing or social distancing can be patchy.
The head of the World Health Organization, Tedros Adhanom Ghebreyesus, said a vaccine was needed urgently but that Europe could not afford to rely on hopes of a new drug.
"We may be tired of COVID-19 but it is not tired of us," Tedros told the Paris Peace Forum, an annual event that is focused this year on fostering global cooperation to beat the pandemic. "European countries are struggling but the virus has not changed significantly, nor the measures to stop it." (Reporting by Reuters bureaux around Europe; Writing by Mark Bendeich, James Mackenzie; Editing by Catherine Evans)
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